Abstract
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 (EFn) tended to that of the intrinsic Fermi level (EFi) (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 EFn 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.
Original language | English (US) |
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Article number | 355101 |
Journal | Journal of Physics D: Applied Physics |
Volume | 48 |
Issue number | 35 |
DOIs | |
State | Published - Sep 9 2015 |
Keywords
- ITO/SiO/c-Si
- open-circuit voltage
- short-circuit current
- temperature response
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Acoustics and Ultrasonics
- Surfaces, Coatings and Films