Browsing by Author "Tung, Chao-Ming"

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Investigation of Degradation of Single-Cell PV Module by Pressure Cooker Test and Damp Heat Test
(2016-01-01)
Tung, Chao-Ming
;
Li, Yu-Tai
;
Yang, Wei-Lun
;
Wu, Hung-Sen
;
Yu, Peichen
Accelerated methods for evaluating thermo humidity resistance of single-cell PV module are demonstrated with standard damp heat test (DH) and non-standard pressure cooker test (PCT). We investigated the failure mechanism of PCT. Our result shows testing under PCT more than 121 degrees C has fast degradation compared to other condition.
Photon recycling characteristics of InGaAs/GaAsP multiple quantum well solar cells incorporating a spectrally selective filter and distributed Bragg reflector
(2019-12-09)
Hong, Chung-Yu
;
Wang, Yi-Chin
;
Su, Yu-Chih
;
Tsai, Jia-Ling
;
Tung, Chao-Ming
Photon management plays a vital role in the power conversion efficiency of III-V semiconductor solar cells. However, the photon recycling characteristics of GaAs-based multi-quantum-well (MQW) solar cells employed different optical designs had yet been fully explored. In this work, we investigate the impact of the spectrally selective filter (SSF) and distributed Bragg reflector (DBR) on the photovoltaic characteristics of single-junction, strain-balanced In0.1Ga0.9As/ GaAs0.85P0.15 MQW solar cells. Specifically, the SSFs with cutoff wavelengths of 880, 910, and 940 nm are designed and implemented on MQW solar cells with and without the incorporation of a rear DBR. Photon confinement in the vertical direction is verified based on the characterizations of reflectance, electroluminescence, and external quantum efficiency. We show that the photon confinement reduces the saturation current density, up to 26 times and 3 times for the 880 nm SSF-MQW and SSF-MQW-DBR devices, respectively, compared to that of the 940 nm devices. Furthermore, by comparing the SSF-MQW-DBR solar cells under simulated one-sun and concentrated illumination conditions, the open-circuit voltage exhibits a maximal net increase for the 910 nm SSF due to tradeoff between the short-circuit and saturation current density. The proposed SSF design may offer a viable approach to boost the performance of GaAs-based MQW solar cells. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Photovoltaic Characteristics of Multiple Quantum Well Solar Cells with Distributed Bragg Reflector and Selective Filters
(2016-01-01)
Hong, Chung-Yu
;
Wang, Yi-Chin
;
Hung, Mu-Min
;
Su, Yu-Chih
;
Tsai, Jia-Ling
We investigate the photon recycling characteristics of single junction solar cells incorporating 50-pairs multiple quantum wells (MQW) to exploit the high radiative recombination rate in one-dimensional carrier-confinement structures. In particular, we systematically compare solar cells with monolithically grown distributed Bragg reflectors (DBRs), as well as selective filters (SFs) with cutoff wavelengths of 880, 910, and 930 nm under standard and concentrated illumination conditions. Optical confinement in the vertical direction is verified based on the reflective spectra and electroluminescence properties. Consequently, the photo-recycling effect manifests under concentrated conditions, where the maximal open circuit voltage difference, by 12mV under 200x illumination, is achieved for MQW solar cells incorporating both the DBR and the 910-nm-cutoff SF, compared to those without the DBR or SFs. It is also revealed that the fill factor (FF) is also affected by the photon recycling effect, where incorporating SF results in the FF enhancement compared to the counterpart without the SF and the enhancement is higher for those with DBRs than without the DBRs.