Search

Your search keyword '"Duenow, Joel"' showing total 138 results
Start Over Author "Duenow, Joel"
138 results on '"Duenow, Joel"'

2. Identifying optimal photovoltaic technologies for underwater applications

Author

Röhr, Jason A., Sartor, Ed, Duenow, Joel N., Qin, Zilun, Meng, Juan, Lipton, Jason, Maclean, Stephen A., Römer, Udo, Nielsen, Michael P., Zhao, Suling, Kong, Jaemin, Reese, Matthew O., Steiner, Myles A., Ekins-Daukes, N. J., and Taylor, André D.

Subjects
Physics - Applied Physics
Abstract

Improving solar energy collection in aquatic environments would allow for superior environmental monitoring and remote sensing, but the identification of optimal photovoltaic technologies for such applications is challenging as evaluation requires either field deployment or access to large water tanks. Here, we present a simple bench-top characterization technique that does not require direct access to water and therefore circumvents the need for field testing during initial trials of development. Employing LEDs to simulate underwater solar spectra at various depths, we compare Si and CdTe solar cells, two commercially available technologies, with GaInP cells, a technology with a wide band gap close to ideal for underwater solar harvesting. We use this method to show that while Si cells outperform both CdTe and GaInP under terrestrial AM1.5G solar irradiance, both CdTe and GaInP outperform Si at depths > 2 m, with GaInP cells operating with underwater efficiencies exceeding 51%., Comment: All supplementary information can be found at the end of the main text (before References); 17 pages; 4 main figures; Manuscript has been accepted into iScience

Published
2021

15. Back-surface recombination, electron reflectors, and paths to 28% efficiency for thin-film photovoltaics: A CdTe case study.

Author

Duenow, Joel N. and Metzger, Wyatt K.

Subjects
*THIN films, *SURFACE recombination, *SILICON solar cells, *ELECTRONS, *SOLAR reflectors, *CADMIUM telluride
Abstract

As thin-film and silicon solar technologies mature, questions emerge about the upper bounds of thin-film solar performance and realistic experimental paths to reach them. Directions include increasing absorber hole density and bulk lifetime, improving the junction interface, reducing back-surface recombination, and implementing a back-surface electron reflector. Textbook solutions of idealized p-n junctions create a powerful conceptualization of solar cells as predominantly minority-carrier-driven devices. We demonstrate that thin films are distinct, and models often fail to capture the important role of majority-carrier lifetime, leading to contradictions with lifetime measurements and overestimates of potential device improvement from back-surface passivation and/or reflectors. Furthermore, we identify methods to probe majority-carrier lifetime and re-examine the degree to which back-surface passivation and electron reflectors can increase efficiency for a range of common thin-film interface and absorber properties, using current and emerging CdTe technology as an example. Results indicate that a practical approach is to focus first on improving front-interface recombination velocity and the absorber properties, and then on implementing the back-surface passivation or reflector, which can ultimately allow thin-film solar technology to reach 28% efficiency. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

22. Exceeding 200 ns Lifetimes in Polycrystalline CdTe Solar Cells

Author

Ablekim, Tursun, primary, Duenow, Joel N., additional, Perkins, Craig L., additional, Moseley, John, additional, Zheng, Xin, additional, Bidaud, Thomas, additional, Frouin, Berengere, additional, Collin, Stephane, additional, Reese, Matthew O., additional, Amarasinghe, Mahisha, additional, Colegrove, Eric, additional, Johnston, Steve, additional, and Metzger, Wyatt K., additional

Published
2021
Full Text
View/download PDF

26. Thin-Film Solar Cells with 19% Efficiency by Thermal Evaporation of CdSe and CdTe

Author

Ablekim, Tursun, primary, Duenow, Joel N., additional, Zheng, Xin, additional, Moutinho, Helio, additional, Moseley, John, additional, Perkins, Craig L., additional, Johnston, Steven W., additional, O’Keefe, Patrick, additional, Colegrove, Eric, additional, Albin, David S., additional, Reese, Matthew O., additional, and Metzger, Wyatt K., additional

Published
2020
Full Text
View/download PDF

27. Cathodoluminescence spectrum imaging analysis of CdTe thin-film bevels.

Author

Moseley, John, Al-Jassim, Mowafak M., Guthrey, Harvey L., Burst, James M., Duenow, Joel N., Ahrenkiel, Richard K., and Metzger, Wyatt K.

Subjects
CATHODOLUMINESCENCE, ELECTRONS, SOLAR cells, ELLIPSOMETRY, THIN films
Abstract

We conducted T = 6K cathodoluminescence (CL) spectrum imaging with a nanoscale electron beam on beveled surfaces of CdTe thin films at the critical stages of standard CdTe solar cell fabrication. We find that the through-thickness CL total intensity profiles are consistent with a reduction in grain-boundary recombination due to the CdCl2 treatment. The color-coded CL maps of the near-band-edge transitions indicate significant variations in the defect recombination activity at the micron and sub-micron scales within grains, from grain to grain, throughout the film depth, and between films with different processing histories. We estimated the grain-interior sulfur-alloying fraction in the interdiffused CdTe/CdS region of the CdCl2-treated films from a sample of 35 grains and found that it is not strongly correlated with CL intensity. A kinetic rate-equation model was used to simulate grain-boundary (GB) and grain-interior CL spectra. Simulations indicate that the large reduction in the exciton band intensity and relatively small decrease in the lower-energy band intensity at CdTe GBs or dislocations can be explained by an enhanced electron-hole non-radiative recombination rate at the deep GB or dislocation defects. Simulations also show that higher GB concentrations of donors and/or acceptors can increase the lower-energy band intensity, while slightly decreasing the exciton band intensity. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
View/download PDF

33. Synthesis of CdSeCdSexTe1-x/CdTe for graded solar cells

Author

Zheng, Xin, primary, Kuciauskas, Darius, additional, Moseley, John, additional, Colegrove, Eric, additional, Albin, David, additional, Moutinho, Helio, additional, Duenow, Joel, additional, Harvey, S., additional, Ablekim, Tursun, additional, Ferguson, Andrew, additional, Sivananthan, Siva, additional, and Metzger, Wyatt K., additional

Published
2019
Full Text
View/download PDF

36. Tailoring MgZnO/CdSeTe Interfaces for Photovoltaics

Author

Ablekim, Tursun, primary, Perkins, Craig, additional, Zheng, Xin, additional, Reich, Carey, additional, Swanson, Drew, additional, Colegrove, Eric, additional, Duenow, Joel N., additional, Albin, David, additional, Nanayakkara, Sanjini, additional, Reese, Matthew O., additional, Shimpi, Tushar, additional, Sampath, Walajabad, additional, and Metzger, Wyatt K., additional

Published
2019
Full Text
View/download PDF

37. Dual-Wavelength Time-Resolved Photoluminescence Study of CdSexTe1-x Surface Passivation via MgyZn1-yO and Al2O3

Author

McGott, Deborah, Good, Brian, Fluegel, Brian, Duenow, Joel N., Wolden, Colin, and Reese, Matthew

Abstract

Voltage loss is currently one of the biggest challenges facing cadmium telluride (CdTe) based photovoltaics. Determining the location(s) of major voltage loss within the device stack (e.g., front/back interface, grain boundaries) is therefore of primary interest. Here, we present a custom-built time-resolved photoluminescence system with two excitation wavelengths—670 (standard) and 405 nm—to probe the device stack at depths of approximately 130 and 35 nm, respectively; their comparison helps differentiate interface and bulk contributions to carrier lifetime. We apply this system to examine the passivation effect of two significant recent advances in CdTe: the incorporation of Se to form graded CdSexTe1-x and the replacement of CdS with MgyZn1-yO. It is found that x = 0.2 Se is required to obtain lifetime improvements, primarily in the bulk. Additionally, evidence for trapping at the MgyZn1-yO/CdSexTe1-x interface was observed. This indicates further work is required to sufficiently passivate the front interface.

Published
2022
Full Text
View/download PDF

38. Se diffusion in CdTe thin films for photovoltaics.

Author

Colegrove, Eric, Zheng, Xin, Ablekim, Tursun, Duenow, Joel N, Perkins, Craig L, Moutinho, Helio R, and Metzger, Wyatt K

Subjects
KIRKENDALL effect, THIN films, AUGER electron spectroscopy, DIFFUSION kinetics, DIFFUSION, INTERFACES (Physical sciences)
Abstract

Manipulating CdSeTe bandgrading to enhance photocurrent and carrier lifetime is an essential part of high-performance CdTe photovoltaics (PVs). In this work, we examine Se diffusion kinetics in single-crystal and polycrystalline CdTe during deposition, thermal annealing, and CdCl2 treatments. Se distributions are determined by dynamic secondary-ion-mass spectroscopy and Auger electron spectroscopy depth profiling and coupled with electron backscatter diffraction images of the crystalline structure. Effective bulk and grain boundary diffusion coefficients are determined by analytical models and discussed in the context of processing and film morphology. Se is found to diffuse in CdTe at much higher rates during CdCl2 treatments than with thermal processing alone. GB diffusion also occurs at a significantly faster rate than bulk diffusion. As a result of these two effects, the near interface bulk and GB Se diffusion during CdCl2 treatments dominates the bandgrading profiles in CdTe PVs. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

39. Influence of CdTe Deposition Temperature and Window Thickness on CdTe Grain Size and Lifetime After CdCl 2 Recrystallization

Author

Amarasinghe, Mahisha, primary, Sivananthan, Siva, additional, Metzger, Wyatt K., additional, Colegrove, Eric, additional, Moutinho, Helio, additional, Albin, David, additional, Duenow, Joel, additional, Johnston, Steve, additional, Kephart, Jason, additional, Sampath, Walajabad, additional, and Al-Jassim, Mowafak, additional

Published
2018
Full Text
View/download PDF

40. Obtaining Large Columnar CdTe Grains and Long Lifetime on Nanocrystalline CdSe, MgZnO, or CdS Layers

Author

Amarasinghe, Mahisha, primary, Colegrove, Eric, additional, Moseley, John, additional, Moutinho, Helio, additional, Albin, David, additional, Duenow, Joel, additional, Jensen, Soren, additional, Kephart, Jason, additional, Sampath, Walajabad, additional, Sivananthan, Siva, additional, Al‐Jassim, Mowafak, additional, and Metzger, Wyatt K., additional

Published
2018
Full Text
View/download PDF

43. Enhancing P-Type Doping in Polycrystalline CdTe Films

Author

McCandless, Brian, primary, Buchanan, Wayne, additional, Sriramagiri, Gowri, additional, Thompson, Christopher, additional, Duenow, Joel, additional, Albin, David, additional, Jensen, Soren, additional, Moseley, John, additional, Al-Jassim, M., additional, and Metzger, Wyatt K., additional

Published
2017
Full Text
View/download PDF

44. Antimony Diffusion in CdTe

Author

Colegrove, Eric, primary, Harvey, Steven P., additional, Yang, Ji-Hui, additional, Burst, James M., additional, Duenow, Joel N., additional, Albin, David S., additional, Wei, Su-Huai, additional, and Metzger, Wyatt K., additional

Published
2017
Full Text
View/download PDF

46. Relationship of Open-Circuit Voltage to CdTe Hole Concentration and Lifetime

Author

Duenow, Joel N., primary, Burst, James M., additional, Albin, David S., additional, Reese, Matthew O., additional, Jensen, Soren A., additional, Johnston, Steven W., additional, Kuciauskas, Darius, additional, Swain, Santosh K., additional, Ablekim, Tursun, additional, Lynn, Kelvin G., additional, Fahrenbruch, Alan L., additional, and Metzger, Wyatt K., additional

Published
2016
Full Text
View/download PDF

47. Interface Characterization of Single-Crystal CdTe Solar Cells With VOC > 950 mV

Author

Burst, James M., primary, Duenow, Joel N., additional, Kanevce, Ana, additional, Moutinho, Helio R., additional, Jiang, Chun Sheng, additional, Al-Jassim, Mowafak M., additional, Reese, Matthew Owen, additional, Albin, David S., additional, Aguiar, Jeffrey A., additional, Colegrove, Eric, additional, Ablekim, Tursun, additional, Swain, Santosh K., additional, Lynn, Kelvin G., additional, Kuciauskas, Darius, additional, Barnes, Teresa M., additional, and Metzger, Wyatt K., additional

Published
2016
Full Text
View/download PDF

49. Resetting the defect chemistry in CdTe

Author

Metzger, Wyatt K., primary, Burst, James, additional, Albin, David, additional, Colegrove, Eric, additional, Moseley, John, additional, Duenow, Joel, additional, Farrell, Stuart, additional, Moutinho, Helio, additional, Reese, Matt, additional, Johnston, Steve, additional, Barnes, Teresa, additional, Perkins, Craig, additional, Guthrey, Harvey, additional, and Al-Jassim, Mowafak, additional

Published
2015
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results