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Long‐term conversion efficiency characteristics of thin film solar cells
Author(s) -
Machida Sadayuki,
Tani Tatsuo
Publication year - 2001
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/eej.1097
Subject(s) - materials science , energy conversion efficiency , optoelectronics , photovoltaic system , solar cell , thin film , tandem , cadmium telluride photovoltaics , radiation , irradiation , optics , electrical engineering , composite material , physics , engineering , nanotechnology , nuclear physics
Abstract For the optimum design of a photovoltaic power generation system, it is necessary to accurately estimate their annual power output. However, the output of a thin film solar cell (in this paper, layered tandem a‐Si and CdS/CdTe) varies with the spectral distribution of solar radiation as well as with the Staebler–Wronski effect. Changes in the spectral distribution of solar radiation are caused by variations in air mass movement and water vapor content of the atmosphere. The output of thin film solar cells is seriously affected because of their narrow spectral response band. The Staebler–Wronski effect is a phenomenon where the photoconductivity degrades by light irradiation and recovers by heating. Since several factors can affect the output in such a way, it is difficult to accurately estimate the power output of thin film solar cells for an entire year. In this paper, we will show a method for calculating the power output from the spectral distribution of solar radiation. We will also attempt to clarify the degradation and recovery due to the Staebler–Wronski effect by making a comparison between the conversion efficiency calculated by this method and the conversion efficiency obtained from measured data. The results revealed that the initial degradation of conversion efficiency of layered tandem a‐Si and CdS/CdTe solar cells are 22 and 15% (including the degradation due to dirt 6 to 7%), and the recovery are 5 and 10%. © 2001 Scripta Technica, Electr Eng Jpn, 137(4): 1–9, 2001