Efficiency enhancement of non-selenized Cu(In,Ga)Se2 solar cells employing scalable low-cost antireflective coating.

Bao-Tang Jheng,Meng-Chyi Wu,Po-Tsun Liu

doi:10.1186/1556-276x-9-331

Abstract

In this study, a non-selenized CuInGaSe2 (CIGS) solar device with textured zinc oxide (ZnO) antireflection coatings was studied. The ZnO nanostructure was fabricated by a low-temperature aqueous solution deposition method. With controlling the morphology of the solution-grown tapered ZnO nanorod coatings, the average reflectance of the CIGS solar device decreased from 8.6% to 2.1%, and the energy conversion efficiency increased from 9.1% to 11.1%. The performance improvement in the CuInGaSe2 thin-film solar cell was well explained due to the gradual increase of the refractive index between air and the top electrode of solar cell device by the insertion of the ZnO nanostructure. The results demonstrate a potential application of the ZnO nanostructure array for efficient solar device technology.

Highlights

Antireflection coatings play a major role in enhancing the efficiency of photovoltaic devices by increasing light coupling into the region of the absorber layers
Variations in the growth conditions of nanorod array growth conditions strongly influenced the nanoscale morphology of the textured zinc oxide (ZnO) antireflection coatings, as shown by the Field-emission scanning electron microscope (FESEM) images (Figure 1)
In summary, the effects of ZnO nanorods as a subwavelengthtextured antireflection coating on non-selenized CIGS thinfilm solar cell have been demonstrated in this work

Summary

Introduction

Antireflection coatings play a major role in enhancing the efficiency of photovoltaic devices by increasing light coupling into the region of the absorber layers. The quarter-wavelength thickness antireflection coating is typically designed to suppress optical reflection in a specific range of wavelengths [1,2]. The availability of nanofabrication technology has enabled the engineering of materials with desired antireflection characteristics such as electron beam lithography and dry etching, which have been widely used to fabricate different antireflection nanostructures [3,4]. They require expensive cost of equipment and technology for fabricating nanostructures on large-area solar cells.

Methods

Results

Conclusion