Enhancement of Performance of a-Si:H Solar Cells by Introducing a p-nc-SiOx:H Nanostructure Buffer Layer

Abstract

In this work, single n-i-p solar cells based on hydrogenated amorphous silicon (a-Si:H) are analyzed using one dimensional AMPS-1D (Analysis of Microelectronic and Photonic Structures) code. Effect of introducing a p-layer based on hydrogenated nanocrystalline silicon oxide (p-nc-SiOx:H) as a buffer layer at i/p interface instead of i-layer based on hydrogenated amorphous silicon carbide (i-a-SiC:H) is analyzed. It is found that the incorporation of p-nc-SiOx:H buffer layer at i/p interface reduces the band mismatch between i-a-Si:H absorber layer and p+-nc-SiOx:H window layer and minimizes the defect density near interface. It is also obtained that the spectral response of the solar cell has improved in the wavelength range from 0.48 to 0.7 μm with using p-nc-SiOx:H window/p-nc-SiOx:H buffer dual p-layers. So, an enhancement of the output solar cell performances with using p-nc-SiOx:H buffer layer has obtained. In this case, the short circuit current (Jsc) increases from 10.18 mA/cm2 with i-a-SiC:H buffer layer to 13.44 mA/cm2 with p-nc-SiOx:H buffer layer, the open circuit voltage (VOC) improves from 930 mV to 941 mV and the fill factor (FF) increases from 74.2 % to 76.5 %. As a consequence, the conversion efficiency increases from 7.03 % to 9.67 %.