"Hybrid Silicon Nanocone–Polymer Solar Cells"

Sangmoo Jeong: Erik C. Garnett, Shuang Wang, Zongfu Yu, Shanhui Fan, Mark L. Brongersma, Michael D. McGehee, Yi Cui ; Nano Letters, 04/30/12.

Additional Authors: Erik C. Garnett, Shuang Wang, Zongfu Yu, Shanhui Fan, Mark L. Brongersma, Michael D. McGehee, Yi Cui

Abstract:

Recently, hybrid Si/organic solar cells have been studied for low-cost Si photovoltaic devices because the Schottky junction between the Si and organic material can be formed by solution processes at a low temperature. In this study, we demonstrate a hybrid solar cell composed of Si nanocones and conductive polymer. The optimal nanocone structure with an aspect ratio (height/diameter of a nanocone) less than two allowed for conformal polymer surface coverage via spin-coating while also providing both excellent antireflection and light trapping properties. The uniform heterojunction over the nanocones with enhanced light absorption resulted in a power conversion efficiency above 11%. Based on our simulation study, the optimal nanocone structures for a 10 μm thick Si solar cell can achieve a short-circuit current density, up to 39.1 mA/cm2, which is very close to the theoretical limit. With very thin material and inexpensive processing, hybrid Si nanocone/polymer solar cells are promising as an economically viable alternative energy solution.