Improved conversion efficiency of amorphous Si solar cells using a mesoporous ZnO pattern.

Bit-Na Go,Kyoung Suk Oh,Heon Lee,Chaehyun Kim,Yang Doo Kim,Hak-Jong Choi

doi:10.1186/1556-276x-9-486

Abstract

To provide a front transparent electrode for use in highly efficient hydrogenated amorphous silicon (a-Si:H) thin-film solar cells, porous flat layer and micro-patterns of zinc oxide (ZnO) nanoparticle (NP) layers were prepared through ultraviolet nanoimprint lithography (UV-NIL) and deposited on Al-doped ZnO (AZO) layers. Through this, it was found that a porous micro-pattern of ZnO NPs dispersed in resin can optimize the light-trapping pattern, with the efficiency of solar cells based on patterned or flat mesoporous ZnO layers increased by 27% and 12%, respectively.

Highlights

An effective light-trapping scheme is an extremely important aspect of Si thin-film solar cell technology, as the inherently thin nature of the light-absorbing layer restricts their long-wavelength light absorption, resulting in a low short-circuit current density (Jsc) and power conversion efficiency (PCE) [1,2,3,4,5,6]
In order to increase the adhesion between the glass substrate and zinc oxide (ZnO) NP resin, the glass surface was subjected to UV-ozone treatment for 5 min to remove impurities and render it hydrophilic [25]
The ZnO NP resin dispersion was formulated using a mixture of 10 g of benzyl methacrylate (BzMA)

Summary

Introduction

An effective light-trapping scheme is an extremely important aspect of Si thin-film solar cell technology, as the inherently thin nature of the light-absorbing layer restricts their long-wavelength light absorption, resulting in a low short-circuit current density (Jsc) and power conversion efficiency (PCE) [1,2,3,4,5,6]. A variety of light-trapping structures have been created in Si thin-film solar cells through the use of nanoimprint lithography [10,11] This process is considered one of the most efficient tools for designing lighttrapping structures, as it offers a number of advantages in terms of the following: high throughput with a large area, high resolution (~10 nm), simplicity, and low cost [12,13,14,15,16]. In addition to the light-scattering effect of a rough surface, refractive index engineering provides another functional technique for increasing the light absorption within Si thin-film solar cells. This is based on the fact that a large portion of incident light is reflected at the

Methods

Results

Conclusion