Based On Crystalline Silicon Thin-Film Beherojunction Solar Cell Research And Simulation

Based on thin film heteroj unction of crystalline silicon, solar cell, as a new type of solar power, has gradually raised the attention of masses of scientists because of its obvious advantages, such as low cost, relatively easy production process and etc. Although recently the battery prepared by various laboratories has the problem of low conversion efficiency, its superiorities of the preparation in low energy consumption and low cost far outweigh the current solar cells with high cost, high energy consumption of monocrystalline silicon, and polycrystalline silicon. A new technology, with a layer of transparent crystal precipitating on silicon substrate of semiconductor material, enjoys low cost and high precision, which is easy to realize. Having seen the advantages of solar cells based on crystalline silicon thin film heterojunction, Japanese Sanyo company, has launched HIT battery and now has it industrialized, with the efficiency reaching18%, which provides a good reference for further research. So it is a very promising battery.In this paper, on the basis of previous studies, the author chooses the n-ZnO/p-c-Si heterojunction structure as the core of the battery. ZnO materials with good electro-optical properties are environment friendly, besides, the preparation of raw material costs are lower and purity high; second, ZnO material has the high band gap width of3.37eV suiting for being the battery materials. This paper first conducts computer simulation to n-ZnO/p-c-Si heterojunction, the results of simulation obtained are as followed:the highest open circuit voltage Voc=588.8mV, circuit current Jsc=36.09mA/cm2, fill factor (FF=65.98%, conversion efficiency Eff=14.02%; the n-ZnO/p-c-Si heterojunction solar cell comes to the formation from ZnO thin films prepared by sol-gel method, whose open circuit voltage Voc=0.23V, short circuit current Isc=0.9825mA, fill factor (FF=36.1%, conversion efficiency Eff=0.225%, and it also analyzes the cause low conversion efficiency of the battery. Survey follow-up has found that the efficiency of the battery reduces gradually with the time, and the explanation is that oxided silver electrode and thin layer generated between interface of ZnO and p-c-Si SiO2results in the decrease of battery internal resistance to increase efficiency.