Stretchable and colorless freestanding microwire arrays for transparent solar cells with flexibility

• 来源期刊: 光：科学与应用（英文版）
• 年，卷（期）: 2019,（6）
• 页码范围: 1168-1180
• 页数: 13页
• 语种: 英文

摘要

Transparent solar ceils (TSCs) are emerging devicesthat combine the advantages of visible transparency and light-toelectricity conversion.Currently,existing TSCs are based predominantly on organics,dyes,and perovskites;however,the rigidity and color-tinted transparent nature of those devices strongly limit the utility of the resulting TSCs for realworld applications.Here,we demonstrate a flexible,color-neutral,and high-efficiency TSC based on a freestanding form of n-silicon microwires (SiMWs).Flat-tip SiMWs with controllable spacing are fabricated via deep-reactive ion etching and embedded in a freestanding transparent polymer matrix.The light transmittance can be tuned from ～10to 55％ by adjusting the spacing between the microwires.For TSCs,a heterojunction is formed with a p-type polymer in the top portion of the n-type flat-tip SiMWs.Ohmic contact with an indium-doped ZnO film occurs at the bottom,and the side surface has an Al2O3 passivation layer.Furthermore,slanted-tip SiMWs are developed by a novel solventassisted wet etching method to manipulate light absorption.Finite-difference time-domain simulation revealed that the reflected light from slanted-tip SiMWs helps light-matter interactions in adjacent microwires.The TSC based on the slanted-tip SiMWs demonstrates 8％ efficiency at a visible transparency of 10％ with flexibility.This efficiency is the highest among Si-based TSCs and comparable with that of state-of-the-art neutral-color TSCs based on organic-inorganic hybrid perovskite and organics.Moreover,unlike others,the stretchable and transparent platform in this study is promising for future TSCs.