High-performance vertical graphene nanowall/silicon Schottky junction solar cells with Nafion doping and plasma etching

In this paper, a solar cell based on the vertical graphene nanowall (VGNW)/silicon Schottky junction is doped by polymeric acid (Nafion) and exhibits a high power-conversion efficiency after Ar plasma etching. It is found that, the Nafion doping scheme effectively increases the W-F of VGNW films by similar to 0.5 eV, and simultaneously reduces its average reflectance to similar to 28%. However, there appears to be a poor-conductive Nafion capping layer on the VGNWs after doping, which severely influences the carriers electrical transportation. When a plasma etching process is introduced, the VGNWs buried in the Nafion polymers are exposed, thus reducing its sheet resistance by similar to 20%. The combination of Nafion doping and plasma etching makes the V-bi of the VGNW/n-Si heterojunction greatly improve and exceed 0.6 V, and the FF factor of the VGNW/n-Si solar cells increases from 55.8% to 62.9%. Applying interface passivation and light management, we achieve a significant gain of Jsc and a well-performance VGNW/n-Si Schottky junction solar cell (V-oc of 523 mV, FF of 57.1% and J(sc) of 30.8 mA/cm(2)), whose PCEs up to 9.2% (AM 1.5 G). The present device architecture design and optimisation scheme here are envisaged to be potentially valuable for the doping modification of other 3D materials with similar structures. (c) 2023 Elsevier B.V. All rights reserved.