A Study On Failure Mechanism Of Light Induced Degradation In Amorphous Silicon Solar Cell And Its Reliability Characterization Methods

Adequate supply of energy is the foundation for continuous development of human society. For a long time,the dependence of people on the traditional energy such as coal, oil, natural gas and so on lead to many problem. First of all, the excessive exploitation of these non-renewable energy makes these energy exhausted.Second,the harmful emissions of using these energy cause serious pollution to the environment,thus,it is not conducive to the sustainable development of human.As a result, people begin to focus on new and renewable energy. Solar energy is the outstanding representative of new and renewable energy.Because of the advantage of no pollution, wide distribution,sustainability, safety and reliability and simple maintenance,solar energy is widely used and is a real sense of renewable green energy. Currently, there are three major forms of using solar energy: photo-thermal utilization, photo-chemical utilization, photovoltaic utilization.The utilization of solar convert solar radiation directly into electricity by using solar photovoltaic effect, the core part of it is the solar cell. Currently,there exist many difficulties for Large-scale popularization and application of solar cell as a kind of conventional energy. this is mainly because the price of the generation of solar cell is several times of the conventional energy source. Thus, currently, the study of solar cells is mainly concentrated in three aspects.1) the further reduction of the solar cells cost 2) Constantly improvement of the conversion efficiency 3)look for ways to characterize the reliability of the solar cells.Because of its simple manufacture process, less material used, much available substrates and low cost, research specialist staff pay much attention to amorphous silicon solar cell in the early period. The develop of it is quickly. But there is a key factor that hinders the further development of it. The key factor is the light induced degradation of amorphous silicon solar cell. So it is important to analysis and research the mechanism of this degradation.This paper summarizes the electric properties and the noise properties of the solar cells.Based on analyzing the link of amorphous silicon defects and light induced degradation,as well as the characterization model of light induced degradation, the experiment schedule is established, including the selection of the samples, the selection of experiment condition of light degradation and the description of experiment programme, while the noise test method is proposed based upon the failure mechanism of light induced degradation and the theory of noise. Through the analysis of experiment results, the validity and sensitivity of the noise test are indicated. The relationship of noise in solar cells and electrical parameters are obtained as well. Finally,the 1/f noise model in amorphous solar cell is established based on the link of defects in amorphous material and the two mechanisms of 1/f noise. The research shows that 1/f noise can be used as a kind of sensitive and effective characterization parameter to characterize the process of light induced degradation and reliability of amorphous solar cell.