Solar Cell Performance Under Different Illumination Conditions

Abstract

We numerically simulate performance data of hydrogenated amorphous silicon (a-Si:H) and copper indium gallium diselenide (CIGS) based solar cells for various illumination conditions. For ease of comparison, we model typical single junctions with the very same software. The study allows us to evaluate the cell feasibility in different hybrid electronic systems like smart cards, wrist watches, transponder systems, and mobile sensors. At an illumination intensity of 1 sun, the optical bandgap of the absorber material and the series resistances determine the spectral sensitivity of the solar cell to particular illumination spectra. For intensities of 10-2 suns and so-called D65 spectrum, which represents daylight under cloudy skies, the efficiency of a-Si:H solar cells nearly equates the CIGS cell performance although the AM 1.5 efficiency of the CIGS diode exceeds the one of our a-Si:H cell by more than a factorof two. Infrared-weighted black body radiation leads to superior performance of the CIGS type, whereas for ultraviolet-weighted illumination the a-Si:H cell shows better performance. For intensities below 10-4 suns theexternal shunt resistance dominates the current-voltage characteristics of both cell types, resulting in poor performance independent of the incident spectrum. We complete our study by simulating the solar-powered charging process of a gold capacitor, which serves us as a model for the energy storage within a hybrid electronic system. The charging behavior under various realistic illumination conditions shows particular cellcharacteristics: high open circuit voltages qualify a-Si:H solar cells for electronic systems that require increased voltages and CIGS cells are suited for applications with higher current need.

Thin-Film Silicon Solar Cells on Flexible Substrates

“…It should be noted that the parameters of optimized solar cells based on single crystal silicon exceed parameters of elements based on a-Si in the illumination intensity from medium to low level due to the greater efficiency of conversion. At the same time at a very low level of less than 500 lux solar cell based on a-Si is superior solar cell based on c-Si [2,16]. The conversion efficiency of flexible solar cells based on copper indium gallium diselenide (CIGS), formed on the stainless steel foil, reaches efficiency of 17.4% [17,18] At the same time, the conversion efficiency of cells based on CIGS, formed on PI substrates at low deposition temperature is RADIOELECTRONICS ANDREY G. KAZANSKII reduced to 11% [18][19][20].…”

Overview of the Current State of Flexible Solar Panels and Photovoltaic Materials

“…It should be noted that optimized solar cells based on single-crystal silicon are superior in their parameters to cells based on α-Si in the range of illumination intensities from medium to low levels due to higher conversion efficiency. At the same time, at a very low illumination level of less than 500 lux, the α-Si:H element outperforms the c-Si element [109,110]. A substantial portion of incident energy in photovoltaic solar energy conversion devices goes to waste, primarily due to the necessity of having a gap within the electronic states' continuum of the light-absorbing material, which functions as an absorption threshold.…”

State-of-the-art review of solar design tools and methods for assessing daylighting and solar potential for building-integrated photovoltaics

“…Many researches has been carried out to investigate the behaviour of the PV cells under low light conditions, such as for c-Si [192], a-Si and CIGS [193] and other cell materials [194] [195] [196]. Stamenic et al demonstrated the influence of low light conditions in the simulation of (BIPV) systems [197].…”