Low-temperature preparation of flexible a-Si:H solar cells with hydrogenated nanocrystalline silicon p layer

Abstract

In this paper we report on flexible a-Si:H solar cells prepared on polyethylene naphthalate (PEN) substrates using p-type hydrogenated nanocrystalline silicon thin films (p-nc-Si:H) as the window layer. The p-nc-Si:H films were prepared at low temperature (150 °C) using trimethylboron (TMB) as a dopant gas. The influence of the silane concentration (SC) on the electrical and structural properties of ultra-thin p-nc-Si:H as well as the performance of solar cells on PEN was investigated. The results show that the crystalline fraction and conductivity of p-nc-Si:H thin films diminished, while the deposition rate and RMS roughness of films increased, when the SC increases from 0.53% to 0.8%. For the a-Si:H solar cells on PEN with the non-textured electrodes, the best efficiency of 6.3% was achieved with the p-nc-Si:H thin films deposited at SC = 0.67%.