Low temperature characteristic of ITO/SiOx/c-Si heterojunction solar cell

• Published in: Journal of physics. D, Applied physics Vol. 48; no. 35
• Main Authors: Du, H W, Yang, J, Li, Y, Gao, M, Chen, S M, Yu, Z S, Xu, F, Ma, Z Q
• Format: Journal Article
• Language: English
• Published: IOP Publishing 09.09.2015
• Subjects: c-Si; ITO/SiO; open-circuit voltage; short-circuit current; temperature response
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/48/35/355101

Based on the temperature-dependent measurements and the numerical calculation, the temperature response of the photovoltaic parameters for a ITO/SiOx/c-Si heterojunction solar cell have been investigated in the ascending sorting of 10-300 K. Under unique energy concentrated photon irradiation with the wavelength of 405 nm and power density of 667 mW cm−2, it was found that the short-circuit current (ISC) was nonlinearly increased and the open-circuit voltage (VOC) decreased with temperature. The good passivation of the ITO/c-Si interface by a concomitant SiOx buffer layer leads to the rare recombination of carriers in the intermediate region. The inversion layer model indicated that the band gap of c-silicon was narrowed and the Fermi level of n-type silicon () tended to that of the intrinsic Fermi level () (in the middle of band gap) with the increase of the temperature, which lessened the built-in voltage (VD) and thus the VOC. However, the reduction by 90% of VOC is attributed to the shift of in c-silicon rather than the energy band narrowing. Through the analysis of the current-voltage relationship and the data fitting, we infer that the series resistance (Rs) is not responsible for the increase of ISC, but the absorption coefficient and the depletion-width of c-silicon are the causes of the enhancing ISC. Mostly, the interaction of the photon-generated excess 'cold hole' and the acoustic phonon in n-Si would influence the variation of Iph or ISC with temperature.