Transparent conductive SnO_(2)thin films via resonant Ta doping  

作　　者：Vedaste Uwihoreye Zhenni Yang Jia-Ye Zhang Yu-Mei Lin Xuan Liang Lu Yang Kelvin H.L.Zhang 

机构地区：[1]College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China

出　　处：《Science China Materials》2023年第1期264-271,共8页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(21872116 and 22075232)。

摘　　要：Transparent conductive oxide(TCO)thin films are highly desired as electrodes for modern flat-panel displays and solar cells.Alternative indium-free TCO materials are highly needed,because of the scarcity and the high price of indium.Based on the mechanism of resonant doping,Ta has been identified as an effective dopant for SnO_(2)to achieve highly conductive and transparent TCO.In this work,we fabricated a series of Ta-doped SnO_(2)thin films(Sn_(1-x)Ta_(x)O_(2),x=0.001,0.01,0.02,0.03)with high conductivity and high optical transparency via a low-cost sol-gel spin coating method.The Sn_(0.98)Ta_(0.02)O_(2)film achieves the highest electrical conductivity of 855 S cm-1with a carrier concentration of2.3×10^(20)cm^(-3)and high mobility of 23 cm^(2)V^(-1)s^(-1).The films exhibit a very high optical transparency of 89.5%in the visible light region.High-resolution X-ray photoemission spectroscopy and optical spectroscopy were combined to gain insights into the electronic structure of the Sn_(1-x)Ta_(x)O_(2)films.The optical bandgaps of the films are increased from 3.96 eV for the undoped SnO_(2)to 4.24 eV for the Sn_(0.98)Ta_(0.02)O_(2)film due to the occupation of the bottom of conduction band by free electrons,i.e.,the Burstein-Moss effect.Interestingly,a bandgap shrinkage is also directly observed due to the bandgap renormalization arising from many-body interactions.The double guarantee of transparency and conductivity in Sn_(1-x)Ta_(x)O_(2)films and the low-cost growth method provide a new platform for optoelectronic and solar cell applications.

关 键 词：transparent conductive oxide sol-gel spin coating Ta-doped SnO_(2) electronic structure 

分 类 号：TB33[一般工业技术—材料科学与工程]