Preparation of Highly Transparent (at 450–800 nm) SnO2 Homojunction by Solution Method and Its Photoresponse

Qiannan Ye,Dong Guo,Wei Xu,Rihui Yao,Junbiao Peng,Danqing Hou,Jinxiong Li,Tian Qiu,Honglong Ning,Xu Zhang

doi:10.3390/coatings10040399

Abstract

High-quality SnO2:Si films and SnO2:10 at.% Ga films were prepared by the solution method. The roughness of films is below 1.08 nm, and possess exceptional transparency (>75%) and decent semiconductor properties. Based on this, the SnO2:Si/SnO2: Ga homojunctions with different Si doping concentrations were prepared. It is found that the conductivity of the SnO2:Si thin film gradually increases, and the rectification characteristics of the homojunction are optimized with increasing Si doping content. The SnO2:15 at.% Si/SnO2:10 at.% Ga homogeneous junction has the best performance, the turn-on voltage is as low as 5.6 V, and it also exhibits good unidirectional conductivity. The photoresponse of the SnO2:15 at.% Si/SnO2:10 at.% Ga homojunction under the lights of red, yellow, and purple was explored respectively. The result shows that the device responds strongly to purple light. Compared with the test results in the dark environment, the device current increases by two orders, which is expected to be applied in the field of near-ultraviolet detection.

Highlights

In recent years, with the rapid development of optoelectronic technology, transparent optoelectronic devices have been widely used in many fields due to their excellent optoelectronic properties, such as solar cells [1], light emitting diodes [2,3], photodetectors [4,5], and so on
The SnO2 precursor solution was prepared with 0.564 g of tin chloride dihydrate (SnCl2 ·2H2 O, Aladdin reagent, analysis pure 98%) and 5 mL of ethylene glycol methyl ether (CH3 OCH2 CH2 OH, Tianjin Fuyu Fine Chemical Co., Ltd., Tianjin, China, analysis pure 98%)
The root mean square roughness (Sq) of the SnO2 :10 at.% Ga film is as low as operation of theprovides homojunction

Summary

Introduction

With the rapid development of optoelectronic technology, transparent optoelectronic devices have been widely used in many fields due to their excellent optoelectronic properties, such as solar cells [1], light emitting diodes [2,3], photodetectors [4,5], and so on. The highly transparent PN junction is the basic component of many transparent optoelectronic devices. The development of low-cost, high-performance transparent PN junctions is the key to the popularization of transparent optoelectronic devices. The current mainstream TSO materials mainly include tin oxide (SnO2 ), zinc oxide (ZnO), indium oxide (In2 O3 ), etc. Indium is a precious metal, which is expensive and toxic, limiting its market size; ZnO has poor stability and is not resistant to acid and alkali corrosion, which limits its application; SnO2 is non-toxic, environmentally friendly, low-cost, stable and its mechanical wear resistance is good. The optical band gap is 3.67 eV and the 1transparency is excellent

Methods

Results

Conclusion