A simulation approach to improve photocurrent through a double-layer of the emitter in a-Si1-xCx/c-Si heterojunction solar cell

Abstract

Abstract In this work, a simulation approach to improve the contribution of light generated current by the emitter layer is presented. Single emitter layer made of nanocrystalline carbide of silicon is replaced with a double layer of the same compound material but different elemental composition and optical properties in a microcrystalline silicon-based solar cell. Each layer of the emitter is made of carbides of silicon with different carbon to silicon fractions. The simulated study results showcase short circuit current and efficiency up to 37.86 mAcm−2 and 20.56% respectively for the device with a double emitter layer. The quantum efficiency also justifies an increase in photocurrent in the double layer device. This increase is mainly observed in the wavelength range of photons absorbed by the emitter layer. The calculated emitter saturation current density for the same device is as small as 1.7854 × 10−17 Acm−2. Furthermore, a strong dependence of device parameters on the physical properties of the intrinsic layer is observed. The overall results introduce double emitter as a new approach to improve the photocurrent of heterojunction solar cells.