Solution-Processed Cu2ZnSn(S,Se) 4 Thin-Film Solar Cells Using Elemental Cu, Zn, Sn, S, and Se Powders as Source.

Jing Guo,Dongxing Kou,Sixin Wu,Wenhui Zhou,Yingli Pei,Zhengji Zhou

doi:10.1186/s11671-015-1045-6

Abstract

Solution-processed approach for the deposition of Cu2ZnSn (S,Se)4 (CZTSSe) absorbing layer offers a route for fabricating thin film solar cell that is appealing because of simplified and low-cost manufacturing, large-area coverage, and better compatibility with flexible substrates. In this work, we present a simple solution-based approach for simultaneously dissolving the low-cost elemental Cu, Zn, Sn, S, and Se powder, forming a homogeneous CZTSSe precursor solution in a short time. Dense and compact kesterite CZTSSe thin film with high crystallinity and uniform composition was obtained by selenizing the low-temperature annealed spin-coated precursor film. Standard CZTSSe thin film solar cell based on the selenized CZTSSe thin film was fabricated and an efficiency of 6.4 % was achieved.

Highlights

Quaternary semiconductor Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) compounds have received considerable interest as new generations of photovoltaic absorbing materials, due primarily to their suitable band gaps, high absorption coefficient, and low material cost [1]
The Thermogravimetric analysis (TGA) sample was prepared from the CZTSSe precursor solution by preheating at 100 °C for 20 min under N2 atmosphere to remove the low-boiling-point molecules
It was found that the CZTSSe precursor exhibited a relatively fast weight loss between 130 and 300 °C, which may be ascribed that the extensive N − H · · · S hydrogen bonding existed in the precursor solution was broken and the CZTSSe nanocrystal formed at this temperature [30]

Summary

Introduction

Quaternary semiconductor Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) compounds have received considerable interest as new generations of photovoltaic absorbing materials, due primarily to their suitable band gaps, high absorption coefficient, and low material cost [1]. Non-vacuum technologies such as electrodeposition approach [9,10,11], milling dispersion approach [12], nanoparticle-based approach [13,14,15,16], hydrazine-based approach [17,18,19], and sol–gel approach [20,21,22,23,24] are more feasible for industrial production Among those solution-based process, the hydrazine-based deposition has made the great progress, achieving the power conversion efficiency (PCE) of 12.6 % [25]. For CZTS (e) thin film solar cell, it is very crucial to precisely control the elemental composition of quaternary compounds, which regulate the band gap of the semiconductor and further dominate the device performance. In order to adjust the viscosity of the solution for subsequent spin coating, another organic solvent of 2-methoxyethanol was added into the mixed solution

Methods

Results

Conclusion