TY - GEN
T1 - The improved photoresponse of the substrate-free InGaN solar cells with a bottom reflector
AU - Tsai, Chia Lung
AU - Liu, Guan Shan
AU - Wang, Chien Yu
AU - Huang, Ju Ping
AU - Lin, Jia Qing
PY - 2009
Y1 - 2009
N2 - In this study, the laser lift-off (LLO) technique is used to fabricate the substrate-free InGaN thin-film solar cells (TF-SCs). The epitaxial structures consist of 8-pair In0.23Ga0.77N/GaN multiple-quantum-well (MOW), which is sandwiched between the p- and n-GaN to construct the conventional p-i (intrinsic layer)-n solar cells. After the LLO process to remove the sapphire substrate, a silver layer with reflectivity of 97% was deposited onto the bottom of cell to act as the metallic reflector. Under forward bias operation, the fabricated TF-SCs exhibit a low operating voltage of 3.34 V along with an ideality factor of 6 V. Both of which are comparable to their counterparts that reveals the electrical property of device does not damage after the LLO process. On the other hand, it is observed that the spectral response of the InGaN solar cells changes significantly as the incident wavelength below 510 nm. This wavelength corresponds to the energy transition (∼ 2.43 eV) between the first electron and hole energy level of the In 0.23Ga0.77N/GaN well. Since part of the unabsorbed photons can be re-reflected by the bottom reflector, the TF-SCs show the enhanced photoresponse as compared to the normal solar cells with the sapphire substrate. Finally, the conversion efficiency of the TF-SC is 1.6 times larger than the normal InGaN solar cell under one sunAM 1.5G spectrum.
AB - In this study, the laser lift-off (LLO) technique is used to fabricate the substrate-free InGaN thin-film solar cells (TF-SCs). The epitaxial structures consist of 8-pair In0.23Ga0.77N/GaN multiple-quantum-well (MOW), which is sandwiched between the p- and n-GaN to construct the conventional p-i (intrinsic layer)-n solar cells. After the LLO process to remove the sapphire substrate, a silver layer with reflectivity of 97% was deposited onto the bottom of cell to act as the metallic reflector. Under forward bias operation, the fabricated TF-SCs exhibit a low operating voltage of 3.34 V along with an ideality factor of 6 V. Both of which are comparable to their counterparts that reveals the electrical property of device does not damage after the LLO process. On the other hand, it is observed that the spectral response of the InGaN solar cells changes significantly as the incident wavelength below 510 nm. This wavelength corresponds to the energy transition (∼ 2.43 eV) between the first electron and hole energy level of the In 0.23Ga0.77N/GaN well. Since part of the unabsorbed photons can be re-reflected by the bottom reflector, the TF-SCs show the enhanced photoresponse as compared to the normal solar cells with the sapphire substrate. Finally, the conversion efficiency of the TF-SC is 1.6 times larger than the normal InGaN solar cell under one sunAM 1.5G spectrum.
UR - http://www.scopus.com/inward/record.url?scp=77951562036&partnerID=8YFLogxK
U2 - 10.1109/PVSC.2009.5411462
DO - 10.1109/PVSC.2009.5411462
M3 - 会议稿件
AN - SCOPUS:77951562036
SN - 9781424429509
T3 - Conference Record of the IEEE Photovoltaic Specialists Conference
SP - 2051
EP - 2054
BT - 2009 34th IEEE Photovoltaic Specialists Conference, PVSC 2009
T2 - 2009 34th IEEE Photovoltaic Specialists Conference, PVSC 2009
Y2 - 7 June 2009 through 12 June 2009
ER -