TY  - JOUR
AU  - Li, X.
AU  - Shen, K.
AU  - Li, Q.
AU  - Deng, Y.
AU  - Zhu, P.
AU  - Wang, D.
PY  - 2018//
TI  - Roll-over behavior in current-voltage curve introduced by an energy barrier at the front contact in thin film CdTe solar cell
JO  - Solar Energy
SP  - 27
EP  - 34
VL  - 165
KW  - AlO HRT layer
KW  - Band alignment
KW  - CdTe solar cell
KW  - Roll-over behavior
N2  - Roll-over phenomenon in the current–voltage (J–V) curve is often observed in a CdTe thin film solar cell. The roll-over phenomenon, which is occurred near the open-circuit voltage in a light J–V curve, is due to Schottky energy barrier formed at the CdTe/metal interface in a CdTe solar cell back contact. In this study we report a J–V roll-over phenomenon which is induced by an energy barrier at the front contact of a CdTe solar cell. Two kinds of oxides, namely, Al2O3 and SnO2, were deposited as high-resistance transparent (HRT) layer between the window layer CdS and the fluorine doped tin oxide (FTO) front electrode in CdTe solar cells. These two oxides present much different electronic band alignment with FTO and CdS. SnO2 formed almost no energy barrier with CdS, this allowed smooth transport for photo-generated electrons from CdTe to CdS and FTO. However, Al2O3 formed a high energy barrier with CdS. The rather high energy barrier with a value of 3.43 eV at the CdS/Al2O3 interface induced a J–V roll-over phenomenon in a CdTe thin film solar cell, which dramatically led to a quick decrease for the cell device efficiency. The electron transport at the FTO/Al2O3/CdS interface is governed by tunneling effect. The results presented in this study demonstrate that the band structure at the front electrode plays an important role for the performance of a CdTe thin film solar cell.
SN  - 0038-092x
UR  - https://www.sciencedirect.com/science/article/pii/S0038092X18302081
N1  - exported from refbase (http://www.uhydro.de/base/show.php?record=187), last updated on Fri, 26 Jan 2024 13:19:04 +0100
ID  - Li_etal2018
ER  -