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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2014., Cataloged from PDF version of thesis., Includes bibliographical references (pages 147-164)., More than two billion people in the world have little or no access to electricity. To be empowered they need robust and lightweightrenewable energy conversion technologies that can be easily transported with high yield from our manufacturing centers to their (often) rural homes. Few conventional photovoltaic technologies are robust enough to fill this need, however organic photovoltaics (OPVs) are ideal candidates due to their potential to be ultra-lightweight and flexible. However, this promising technology is currently limited by its relatively low power conversion efficiencies. This doctoral dissertation seeks to speed the eming of this promising technology. As a proof of concept for the accessibility and ultra-lightweight of OPVs, we integrate vapor-processed carbon-based electrodes and sub-30nm-thin encapsulations in organic photovoltaics, leading to the demonstration of monolithic, robust solar cell arrays as well as the first ever solar cells fabricated directly on paper. Furthermore, we have developed and advanced two unconventional approaches to enhancing power conversion efficiency via conventional methods: (1) optimization of multijunction efficiency via computational optical interference modeling and subcell photocurrent balance quantization and control, and (2) novel implementation of conventional vapor processing methods in the formation of molecular semiconductor crystals. This work has confirmed the potential of carbon-based materials to enable robust, ultra-lightweight, efficient solar arrays, thus advancing their capacity to empower our brothers and sisters even at the ends of the earth., by Jill Annette (Rowehl) Macko., Ph. D.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2014., Cataloged from PDF version of thesis., Includes bibliographical references (pages 147-164)., More than two billion people in the world have little or no access to electricity. To be empowered they need robust and lightweightrenewable energy conversion technologies that can be easily transported with high yield from our manufacturing centers to their (often) rural homes. Few conventional photovoltaic technologies are robust enough to fill this need, however organic photovoltaics (OPVs) are ideal candidates due to their potential to be ultra-lightweight and flexible. However, this promising technology is currently limited by its relatively low power conversion efficiencies. This doctoral dissertation seeks to speed the eming of this promising technology. As a proof of concept for the accessibility and ultra-lightweight of OPVs, we integrate vapor-processed carbon-based electrodes and sub-30nm-thin encapsulations in organic photovoltaics, leading to the demonstration of monolithic, robust solar cell arrays as well as the first ever solar cells fabricated directly on paper. Furthermore, we have developed and advanced two unconventional approaches to enhancing power conversion efficiency via conventional methods: (1) optimization of multijunction efficiency via computational optical interference modeling and subcell photocurrent balance quantization and control, and (2) novel implementation of conventional vapor processing methods in the formation of molecular semiconductor crystals. This work has confirmed the potential of carbon-based materials to enable robust, ultra-lightweight, efficient solar arrays, thus advancing their capacity to empower our brothers and sisters even at the ends of the earth., by Jill Annette (Rowehl) Macko., Ph. D.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012., Cataloged from PDF version of thesis., Includes bibliographical references (p. 87-89)., In this thesis, a novel diffusion-based contact-printing technology is investigated, by which a wide variety of low molecular weight organic materials can be patterned without added temperature, pressure, or chemical processing, with just the use of relief-patterned polymeric (PDMS) stamps. It is determined that the diffusion of organic molecules into the polymer matrix is a solvent-assisted process in which mobile oligomers aid in the removal of organic material. It is further shown that using composite stamps, organic films can be patterned at a sub-100 nm length scale. Among other features, this patterning process has enabled patterning of Organic Light Emitting Diodes on a wavelength scale to reduce total internal reflection and thereby enhance the outcoupling of light from the device., by Sulinya Ramanan., M.Eng.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012., Cataloged from PDF version of thesis., Includes bibliographical references (p. 87-89)., In this thesis, a novel diffusion-based contact-printing technology is investigated, by which a wide variety of low molecular weight organic materials can be patterned without added temperature, pressure, or chemical processing, with just the use of relief-patterned polymeric (PDMS) stamps. It is determined that the diffusion of organic molecules into the polymer matrix is a solvent-assisted process in which mobile oligomers aid in the removal of organic material. It is further shown that using composite stamps, organic films can be patterned at a sub-100 nm length scale. Among other features, this patterning process has enabled patterning of Organic Light Emitting Diodes on a wavelength scale to reduce total internal reflection and thereby enhance the outcoupling of light from the device., by Sulinya Ramanan., M.Eng.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012., Cataloged from PDF version of thesis., Includes bibliographical references (p. 87-89)., In this thesis, a novel diffusion-based contact-printing technology is investigated, by which a wide variety of low molecular weight organic materials can be patterned without added temperature, pressure, or chemical processing, with just the use of relief-patterned polymeric (PDMS) stamps. It is determined that the diffusion of organic molecules into the polymer matrix is a solvent-assisted process in which mobile oligomers aid in the removal of organic material. It is further shown that using composite stamps, organic films can be patterned at a sub-100 nm length scale. Among other features, this patterning process has enabled patterning of Organic Light Emitting Diodes on a wavelength scale to reduce total internal reflection and thereby enhance the outcoupling of light from the device., by Sulinya Ramanan., M.Eng.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008., Cataloged from PDF version of thesis., Includes bibliographical references (p. 61-62)., Chemosensors hold many vital applications in today's world, particularly as detectors for explosives. There is still vast room for improvement as other technologies-particularly those of explosives-continue to evolve and expand. Herein, we develop a novel device structure with the potential for much higher sensitivity. The lateral bilayer photoconductor is comprised of an exciton generation layer (EGL) and a charge transport layer (CTL). This separates the functionality of chemical sensing from the charge transport, allowing each film to be independently optimized. As a further improvement on this structure, we introduce a spacer layer to separate charge carriers in the EGL and the CTL, reducing bimolecular recombination at the interface. As a proof of concept, we fabricate and characterize lateral multilayer photoconductors composed of small molecule organic films. It is experimentally demonstrated that the utilization of a spacer layer can produce an order of magnitude enhancement in quantum efficiency over the of a spacer layer can produce an order of magnitude enhancement in quantum efficiency over the The work reported here provides encouraging results in the fields of chemosensors and organic optoelectronics., by Jill A. Rowehl., S.B.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008., Includes bibliographical references (p. 75-76)., Conventional Flash memory devices face a scaling issue that will impede memory scaling beyond the 50nm node: a reliability issue involving the tunneling oxide thickness and charge retention. A possible solution is to replace the continuous floating gate, where charge is stored, with a segmented charge storage film, so that leakage through defects in the tunneling oxide would be localized. We first explored using quantum dots as possible floating gate replacements. After conducting simulations, we established the need for the smallest possible segmented structures. This led us to the use of molecular films as floating gates in non-volatile flash memories. As an example, a single organic molecule of 3,4,9,10 -parylene tetracarboxylic dianhydride (PTCDA) occupies lnm2 in area and is capable of storing and retaining a single charge. If a defect is present in the tunneling oxide below the floating gate, only a few molecules of PTCDA would be affected due to poor lateral conduction between PTCDA molecules. We can, therefore, project that such molecular thin films of PTCDA are likely to meet demanding size and packing density requirements of advancing flash memory technology., by Hassen Abdu., M.Eng.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008., Includes bibliographical references (p. 75-76)., A fully lithographic process at near-room-temperature was developed for the purpose of fabricating transistors based on metal-oxide channel materials. The combination of indium tin oxide (ITO) as the source/drain electrodes, zinc indium oxide (ZIO) as the semiconducting channel, and parylene as the dielectric was used to demonstrate the feasibility of such a low temperature lithographic process. This low processing temperature, roughly 150 C, enables the use of unconventional substrates such as glass or plastics, and can therefore simplify the fabrication of devices for low-cost, large-area electronics., by Hui Tang., M.Eng.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008., Includes bibliographical references (p. 75-76)., Conventional Flash memory devices face a scaling issue that will impede memory scaling beyond the 50nm node: a reliability issue involving the tunneling oxide thickness and charge retention. A possible solution is to replace the continuous floating gate, where charge is stored, with a segmented charge storage film, so that leakage through defects in the tunneling oxide would be localized. We first explored using quantum dots as possible floating gate replacements. After conducting simulations, we established the need for the smallest possible segmented structures. This led us to the use of molecular films as floating gates in non-volatile flash memories. As an example, a single organic molecule of 3,4,9,10 -parylene tetracarboxylic dianhydride (PTCDA) occupies lnm2 in area and is capable of storing and retaining a single charge. If a defect is present in the tunneling oxide below the floating gate, only a few molecules of PTCDA would be affected due to poor lateral conduction between PTCDA molecules. We can, therefore, project that such molecular thin films of PTCDA are likely to meet demanding size and packing density requirements of advancing flash memory technology., by Hassen Abdu., M.Eng.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008., Includes bibliographical references (p. 141-151)., Organic light emitting devices (OLEDs) are brightly emissive, efficient, have fast switching speeds, and are paper-thin in format, propelling their use as an emerging flat panel display technology. However, two primary challenges prevent OLEDs from dominating the large-area display market: the extension of OLED display lifetime and development of simple, scalable fabrication techniques compatible with small molecule organic thin films. The principle contributions we report are (1) introduction and analysis of a novel optical feedback technique for extending the lifetime of OLED displays (2) the experimental demonstration and theoretical analysis of contact stamping for patterning multi-color OLED displays., by Jennifer J. Yu., Ph.D.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008., Includes bibliographical references (p. 75-76)., A fully lithographic process at near-room-temperature was developed for the purpose of fabricating transistors based on metal-oxide channel materials. The combination of indium tin oxide (ITO) as the source/drain electrodes, zinc indium oxide (ZIO) as the semiconducting channel, and parylene as the dielectric was used to demonstrate the feasibility of such a low temperature lithographic process. This low processing temperature, roughly 150 C, enables the use of unconventional substrates such as glass or plastics, and can therefore simplify the fabrication of devices for low-cost, large-area electronics., by Hui Tang., M.Eng.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008., Includes bibliographical references (p. 75-76)., Conventional Flash memory devices face a scaling issue that will impede memory scaling beyond the 50nm node: a reliability issue involving the tunneling oxide thickness and charge retention. A possible solution is to replace the continuous floating gate, where charge is stored, with a segmented charge storage film, so that leakage through defects in the tunneling oxide would be localized. We first explored using quantum dots as possible floating gate replacements. After conducting simulations, we established the need for the smallest possible segmented structures. This led us to the use of molecular films as floating gates in non-volatile flash memories. As an example, a single organic molecule of 3,4,9,10 -parylene tetracarboxylic dianhydride (PTCDA) occupies lnm2 in area and is capable of storing and retaining a single charge. If a defect is present in the tunneling oxide below the floating gate, only a few molecules of PTCDA would be affected due to poor lateral conduction between PTCDA molecules. We can, therefore, project that such molecular thin films of PTCDA are likely to meet demanding size and packing density requirements of advancing flash memory technology., by Hassen Abdu., M.Eng.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2006., Includes bibliographical references (leaves 76-81)., The cost of manufacturing electronic displays currently limits the range of applications and markets into which it is currently economically feasible to adopt displays. Roll-to-roll manufacturing has been identified by the display industry as a new and fundamentally different manufacturing paradigm that has the potential to significantly reduce the manufacturing cost of a display relative to the conventional approaches used in the industry. This manufacturing cost reduction could have a profound impact on the display industry by not only transforming the display manufacturing infrastructure, but also by permitting electronic displays to penetrate new markets. The purpose of this thesis is to determine how roll-to-roll manufacturing technology could develop and to assess what impact the technology could have on the electronic display manufacturing industry. This work first identifies the material, patterning, and equipment technologies that need to come together in order for roll-to-roll manufacturing to be industrially feasible, and then determines how and if the technology will offer a cost reduction over conventional manufacturing techniques., (cont.) Next, the markets for displays are segmented and analyzed to discern whether niche initial markets exist where roll-to-roll could have a distinctive advantage and gain traction. Competitive technologies such as LCD and modular LED are discussed and it is determined that roll-to-roll displays must compete with LCD technology on the basis of price in the markets in which LCD has incumbency in order to achieve widespread adoption. The display industry structure is analyzed by means of an assessment of the supply chain, intellectual property landscape, financing mechanisms, and business models to understand how partnerships and financial investment risk are salient aspects of the commercialization process. It is concluded that materials cost advantages over current manufacturing approaches and the timing of roll-to-roll technology integration developments relative to the incremental manufacturing cost decreases in competing technologies will ultimately dictate the success of roll-to-roll manufacturing., by Michael Aaron Randolph., M.Eng.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006., Includes bibliographical references (p. 55-56)., Organic LEDs (OLEDs) have the potential to be used to build large-format, thin, flexible displays. Currently, the primary drawback to their usage lies in the difficulty of producing OLEDs which emit light at a constant and predictable brightness over their lifetime. A solution has been proposed which uses organic photo-detectors and optical feedback to control the desired luminosity on a per-pixel basis. This thesis demonstrates the design and fabrication of an integrated silicon control chip and an organic pixel/imaging array, which together form a stable, usable display. The simulation, verification, and testing of this OLED display demonstrates the utility of our solution. In particular, this thesis focuses on the Loop Compensator silicon design and feedback aspects of this circuit. The results demonstrate that the Loop Compensator has the desired DC and frequency characteristics with a measured gain of 100.2 and a variable dominant pole located at digitally-selectable frequencies (using a programmable capacitor array) of 10.8 Hz, 13.5 Hz, 22.8 Hz, and 64.8 Hz, given a clock frequency of 20 kHz., by Kartik S. Lamba., M.Eng.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2006., Includes bibliographical references (leaves 76-81)., The cost of manufacturing electronic displays currently limits the range of applications and markets into which it is currently economically feasible to adopt displays. Roll-to-roll manufacturing has been identified by the display industry as a new and fundamentally different manufacturing paradigm that has the potential to significantly reduce the manufacturing cost of a display relative to the conventional approaches used in the industry. This manufacturing cost reduction could have a profound impact on the display industry by not only transforming the display manufacturing infrastructure, but also by permitting electronic displays to penetrate new markets. The purpose of this thesis is to determine how roll-to-roll manufacturing technology could develop and to assess what impact the technology could have on the electronic display manufacturing industry. This work first identifies the material, patterning, and equipment technologies that need to come together in order for roll-to-roll manufacturing to be industrially feasible, and then determines how and if the technology will offer a cost reduction over conventional manufacturing techniques., (cont.) Next, the markets for displays are segmented and analyzed to discern whether niche initial markets exist where roll-to-roll could have a distinctive advantage and gain traction. Competitive technologies such as LCD and modular LED are discussed and it is determined that roll-to-roll displays must compete with LCD technology on the basis of price in the markets in which LCD has incumbency in order to achieve widespread adoption. The display industry structure is analyzed by means of an assessment of the supply chain, intellectual property landscape, financing mechanisms, and business models to understand how partnerships and financial investment risk are salient aspects of the commercialization process. It is concluded that materials cost advantages over current manufacturing approaches and the timing of roll-to-roll technology integration developments relative to the incremental manufacturing cost decreases in competing technologies will ultimately dictate the success of roll-to-roll manufacturing., by Michael Aaron Randolph., M.Eng.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2006., Includes bibliographical references (leaves 76-81)., The cost of manufacturing electronic displays currently limits the range of applications and markets into which it is currently economically feasible to adopt displays. Roll-to-roll manufacturing has been identified by the display industry as a new and fundamentally different manufacturing paradigm that has the potential to significantly reduce the manufacturing cost of a display relative to the conventional approaches used in the industry. This manufacturing cost reduction could have a profound impact on the display industry by not only transforming the display manufacturing infrastructure, but also by permitting electronic displays to penetrate new markets. The purpose of this thesis is to determine how roll-to-roll manufacturing technology could develop and to assess what impact the technology could have on the electronic display manufacturing industry. This work first identifies the material, patterning, and equipment technologies that need to come together in order for roll-to-roll manufacturing to be industrially feasible, and then determines how and if the technology will offer a cost reduction over conventional manufacturing techniques., (cont.) Next, the markets for displays are segmented and analyzed to discern whether niche initial markets exist where roll-to-roll could have a distinctive advantage and gain traction. Competitive technologies such as LCD and modular LED are discussed and it is determined that roll-to-roll displays must compete with LCD technology on the basis of price in the markets in which LCD has incumbency in order to achieve widespread adoption. The display industry structure is analyzed by means of an assessment of the supply chain, intellectual property landscape, financing mechanisms, and business models to understand how partnerships and financial investment risk are salient aspects of the commercialization process. It is concluded that materials cost advantages over current manufacturing approaches and the timing of roll-to-roll technology integration developments relative to the incremental manufacturing cost decreases in competing technologies will ultimately dictate the success of roll-to-roll manufacturing., by Michael Aaron Randolph., M.Eng.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006., Includes bibliographical references (p. 55-56)., Organic LEDs (OLEDs) have the potential to be used to build large-format, thin, flexible displays. Currently, the primary drawback to their usage lies in the difficulty of producing OLEDs which emit light at a constant and predictable brightness over their lifetime. A solution has been proposed which uses organic photo-detectors and optical feedback to control the desired luminosity on a per-pixel basis. This thesis demonstrates the design and fabrication of an integrated silicon control chip and an organic pixel/imaging array, which together form a stable, usable display. The simulation, verification, and testing of this OLED display demonstrates the utility of our solution. In particular, this thesis focuses on the Loop Compensator silicon design and feedback aspects of this circuit. The results demonstrate that the Loop Compensator has the desired DC and frequency characteristics with a measured gain of 100.2 and a variable dominant pole located at digitally-selectable frequencies (using a programmable capacitor array) of 10.8 Hz, 13.5 Hz, 22.8 Hz, and 64.8 Hz, given a clock frequency of 20 kHz., by Kartik S. Lamba., M.Eng.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2003., Includes bibliographical references (leaves 45-48)., The use of quantum dots as discrete emitters in hybrid organic/inorganic light emitting devices is an attractive approach for producing novel display products. These structures exhibit narrow-band emission tunable across the visible spectrum - characteristics allowing for display devices not possible with current OLEO materials. In this work, quantum dot light emitting devices (QD-LEDs) using small molecule host materials are evaluated as a potential platform for the growing OLEO industry. Specific applications are suggested and the primary technology hurdles identified. A search of relevant patents pertaining to quantum dot synthesis and device structure was conducted to reveal a significant opportunity for the commercialization of QD-LED devices. A business model has been devised based upon several developing companies in the OLEO industry with a focus on licensing of technology as the primary source of revenue., by Choong S. Sohn., M.Eng.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004., Includes bibliographical references (p. 69)., An OLED display has been fabricated and successfully tested with an external optical feedback circuit to demonstrate improvement in uniformity. In addition, the process of making an integrated system with the optical feedback and OLED display on the same substrate is described. Future work on this solution can include using edge emitted light in the optical feedback, which is discussed and analyzed in this paper., by Jennifer J. Yu., M.Eng.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002., Includes bibliographical references (leaves 29-32)., We demonstrate efficient electroluminescence from thin film structures containing core-shell CdSe(ZnS) quantum dots dispersed in molecular organic host materials. In the most efficient devices, excitons are created on the quantum dot sites via energy transfer from organic host molecules, and direct charge injection into the quantum dots is minimized. For quantum dots with core diameter 38 [Angstroms], the electroluminescence spectra peak at 562nm and have full width at half maximum as narrow as 32nm. Saturated color devices have external quantum efficiencies as high as 0.61% at the current density of 7mA/cm². At 125mA/cm², the device luminance is 1900cd/m², which corresponds to a luminescence efficiency of 1.5 cd/A. The yield over hundreds of devices is greater than 90%, indicating a robust material system., by Seth Alexander Coe., S.M.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004., Includes bibliographical references (p. 69)., An OLED display has been fabricated and successfully tested with an external optical feedback circuit to demonstrate improvement in uniformity. In addition, the process of making an integrated system with the optical feedback and OLED display on the same substrate is described. Future work on this solution can include using edge emitted light in the optical feedback, which is discussed and analyzed in this paper., by Jennifer J. Yu., M.Eng.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002., Includes bibliographical references (leaves 29-32)., We demonstrate efficient electroluminescence from thin film structures containing core-shell CdSe(ZnS) quantum dots dispersed in molecular organic host materials. In the most efficient devices, excitons are created on the quantum dot sites via energy transfer from organic host molecules, and direct charge injection into the quantum dots is minimized. For quantum dots with core diameter 38 [Angstroms], the electroluminescence spectra peak at 562nm and have full width at half maximum as narrow as 32nm. Saturated color devices have external quantum efficiencies as high as 0.61% at the current density of 7mA/cm². At 125mA/cm², the device luminance is 1900cd/m², which corresponds to a luminescence efficiency of 1.5 cd/A. The yield over hundreds of devices is greater than 90%, indicating a robust material system., by Seth Alexander Coe., S.M.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004., Includes bibliographical references (leaf 65)., Organic LEDs (OLEDs) offer the potential of ultra low power, portable display technology. The chief barrier to their usage lies in producing OLEDs that will emit light at predictable and consistent amplitudes. We propose the use of optical feedback to generate the desired luminosity pixel by pixel. We implement this technique in an integrated silicon chip. The simulation and verification of fabricated integrated circuits with deposited OLEDs validates the utility of the technique., by Matthew Reid Powell., M.Eng.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002., Includes bibliographical references (leaves 29-32)., We demonstrate efficient electroluminescence from thin film structures containing core-shell CdSe(ZnS) quantum dots dispersed in molecular organic host materials. In the most efficient devices, excitons are created on the quantum dot sites via energy transfer from organic host molecules, and direct charge injection into the quantum dots is minimized. For quantum dots with core diameter 38 [Angstroms], the electroluminescence spectra peak at 562nm and have full width at half maximum as narrow as 32nm. Saturated color devices have external quantum efficiencies as high as 0.61% at the current density of 7mA/cm². At 125mA/cm², the device luminance is 1900cd/m², which corresponds to a luminescence efficiency of 1.5 cd/A. The yield over hundreds of devices is greater than 90%, indicating a robust material system., by Seth Alexander Coe., S.M.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004., Includes bibliographical references (leaf 65)., Organic LEDs (OLEDs) offer the potential of ultra low power, portable display technology. The chief barrier to their usage lies in producing OLEDs that will emit light at predictable and consistent amplitudes. We propose the use of optical feedback to generate the desired luminosity pixel by pixel. We implement this technique in an integrated silicon chip. The simulation and verification of fabricated integrated circuits with deposited OLEDs validates the utility of the technique., by Matthew Reid Powell., M.Eng.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002., Includes bibliographical references (leaves 29-32)., We demonstrate efficient electroluminescence from thin film structures containing core-shell CdSe(ZnS) quantum dots dispersed in molecular organic host materials. In the most efficient devices, excitons are created on the quantum dot sites via energy transfer from organic host molecules, and direct charge injection into the quantum dots is minimized. For quantum dots with core diameter 38 [Angstroms], the electroluminescence spectra peak at 562nm and have full width at half maximum as narrow as 32nm. Saturated color devices have external quantum efficiencies as high as 0.61% at the current density of 7mA/cm². At 125mA/cm², the device luminance is 1900cd/m², which corresponds to a luminescence efficiency of 1.5 cd/A. The yield over hundreds of devices is greater than 90%, indicating a robust material system., by Seth Alexander Coe., S.M.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004., Includes bibliographical references (leaf 65)., Organic LEDs (OLEDs) offer the potential of ultra low power, portable display technology. The chief barrier to their usage lies in producing OLEDs that will emit light at predictable and consistent amplitudes. We propose the use of optical feedback to generate the desired luminosity pixel by pixel. We implement this technique in an integrated silicon chip. The simulation and verification of fabricated integrated circuits with deposited OLEDs validates the utility of the technique., by Matthew Reid Powell., M.Eng.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004., Includes bibliographical references (p. 69)., An OLED display has been fabricated and successfully tested with an external optical feedback circuit to demonstrate improvement in uniformity. In addition, the process of making an integrated system with the optical feedback and OLED display on the same substrate is described. Future work on this solution can include using edge emitted light in the optical feedback, which is discussed and analyzed in this paper., by Jennifer J. Yu., M.Eng.