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In order to investigate the feasibility of applying dye-sensitized solar cells (DSSC) as optical sensors, DSSC and Si photodiode (Si PD) were irradiated by RGB LED with various colors and intensities, and the electrical properties were recorded. The relationships between the electrical properties, color and intensity of light are contrastively analyzed. The open-circuit voltage ( V oc ) of DSSC is larger and much more stable with the variation of light intensity than that of Si PD, while the short-circuit current ( I sc ) of DSSC is relatively smaller than that of Si PD. The colored light is assumed to be monochromatic light with similar color by using conversion algorithm written by Dan Bruton. High relative deviation between the experimental intensity and the calculated incident intensity is found in DSSC and Si PD, confirming the exoterica that RGB-mixed light is not monochromatic in nature though their color is similar. I sc and V oc response time under pulsed irradiation by RGB light were studied, and the results show that I sc rise time of DSSC is ∼150 ms, which is at least three times as long as that of Si PD, and V oc fall time of DSSC is much longer than that of Si PD. [ABSTRACT FROM AUTHOR]

Emerging fluorescent protein-based sensors allow researchers to monitor neural activities via optical recording of the fluorescence signals. This optical method is able to monitor multiple cell signals with ease in identifying individual cells in dense neurocircuitry. To this end, we demonstrate a high-yield passive Si photodiode array, aiming to establish a miniaturized optical recording device toward in-vivo use. Our fabricated array features a high yield (>90%), low detection limit (32 \mu \textW /cm2), and high speed (1000 frames per second for scanning up to 100 pixels). Using a fast I–V measurement setup, we examined the device performance in terms of detection limit and speed. A mapping of the light intensity on the entire array manifests its promise as an on-chip fluorescence imager for optical neural recording. The array routinely consumes sub- 10~\mu \textW power, which is suitable for chronic in vivo use. [ABSTRACT FROM AUTHOR]

Photodetection with high responsivity at the wavelength of 1060 nm is highly desirable for light detection and ranging (LiDAR) as well as the recent emergence of swept-source optical coherent tomography (SS-OCT) applications. However, the absorption coefficient $\alpha $ of Si material at 1060 nm under the bias of 0 V is very low due to its approach to the absorption bandgap edge of Si material. In this letter, the carrier-collection-enhanced structure is proposed, which functions as multiple carrier collection paths, which enhances the external quantum efficiency of photodiodes. An efficient Si photodiode with responsivity of 0.49 A/W at 1060 nm at 0 V is demonstrated, which is 2.5 times of that of commercial products. The cost-effective fabrication of Si photodiodes greatly enhances the system performance of LiDAR and OCT. [ABSTRACT FROM PUBLISHER]

The advancement of deep reactive-ion etching (DRIE) technology has enabled many 3-D structures, and are widely employed in microelectromechanical systems (MEMS). From an electrical point of view, however, those structures have been used as passive components such as capacitors and resistors. To further evolve the utility of future MEMS devices, the authors propose to integrate "active electrical devices" into 3-D MEMS. As an example, vertical trench photodiodes were fabricated on an n-type bulk silicon wafer using DRIE and thermal diffusion of boron. A photocurrent increase from 25% to 70%, and 20% smaller crosstalk was seen in 40-mm deep-trench diodes, as compared to a planar diode made on the same wafer [ABSTRACT FROM PUBLISHER]

Abstract: The degradation behavior for Si p–i–n photodiodes by neutron irradiation at different temperatures was studied. The degradation of the electrical device performance is more pronounced for low-temperature irradiations. Two electron capture levels at and , respectively, were observed by deep level transient spectroscopy. The degradation of the device performance is correlated with the introduction rate of the radiation-induced lattice defects. [Copyright &y& Elsevier]

Results are presented of a detailed study of the effects of high-temperature 4-MeV neutron irradiation on the performance degradation of Si pin photodiodes together with the radiation-induced defects, observed by deep level transient spectroscopy. The degradation of the device performance and the introduction rate of the lattice defects decrease with increasing sample temperature during irradiation. For a 250°C irradiation, the reduction of the reverse current is only 20% of the starting value. This result suggests that the creation and recovery of the radiation damage proceeds simultaneously at high temperatures. Carbon-related complex as hole capture levels is also mainly responsible for the device degradation for high-temperature neutron irradiation. [Copyright &y& Elsevier]