Characterization of microcrystalline I-layer for solar cells prepared in low temperature - plastic compatible process

Abstract

Microcrystalline silicon (mc-Si) films deposited using a Plasma Enhanced Chemical Vapour Deposition (PECVD) process constitute an important material for manufacturing low-cost, large-area thin-film devices, such as solar cells or thin-film transistors. Although the deposition of electronic-grade mc-Si using the PECVD process is now well established, the high substrate temperature required (∼ 300◦C) does not lend itself to electronic devices with flexible form factors fabricated on low-cost plastic substrates. In this study, we first investigated an intrinsic mc-Si layer deposited at plastic-compatible substrate temperatures (150◦C) by characterising the properties of the film and then evaluated its applicability to p-i-n solar cells though device characterisation. When the performance of the solar cell was correlated with film properties, it was found that, although it compared unfavourably with mc-Si deposited at higher temperatures, it remained a very promising option. Nonetheless, further development is required to increase the overall efficiency of mc-Si flexible solar cells.