两步退火法对硫化铅薄膜光电性能的影响  

Effect of Two-Step Annealing on Optoelectronic Properties of Lead Sulfide Thin Films

作　　者：范良朝 黄智 吕全江 刘桂武[1] 乔冠军[1] 刘军林 Fan Liangchao;Huang Zhi;Lu Quanjiang;Liu Guiwu;Qiao Guanjun;Liu Junlin(School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,Jiangsu,China)

机构地区：[1]江苏大学材料科学与工程学院,江苏镇江212013

出　　处：《光学学报》2023年第10期278-284,共7页Acta Optica Sinica

基　　金：江苏省双创团队项目(JSSCTD202146)。

摘　　要：采用先低温O2气氛退火,后高温N2气氛退火的两步退火法工艺,探究了两步退火法对化学浴沉积(CBD)制备的多晶硫化铅(PbS)薄膜光电性能的影响。结果表明,相比于一步退火法,两步退火法所得的PbS薄膜具有较大的晶粒尺寸、较少的晶界和良好的光电性能。在两步退火法中,当第二步退火时间为80 min时,PbS薄膜的响应度为2.33 A·W^(-1),比探测率为1.18×10^(10)cm·H1/2·W^(-1),与一步退火法相比分别提高了259%和236%,即两步退火法可以在传统一步退火法的基础上进一步提高PbS红外光电探测器的性能。Objective Lead sulfide(PbS)is an important semiconductor material in groupⅣ⁃Ⅵsemiconductors with a narrow band gap(0.41 eV)and a large exciton Bohr radius(18 nm)at room temperature.These characteristics make PbS highly sensitive to infrared(IR)radiation,which has led to the widespread use of PbS films in IR detectors,solar cells,gas sensors,and other fields.The as-grown PbS thin films respond poorly to IR and can only be used as highly sensitive IR detectors after sensitization.Annealing in oxygen is an effective method to enhance the photosensitivity of PbS detectors,and oxygen has been proven to be the best sensitizer.Although numerous studies have been carried out on one-step annealing in an oxygen-contained atmosphere,the development of new methods to further improve thin films'responsiveness to IR continues to plague academia and industry.In this work,a new two-step sensitization treatment process for as-grown PbS thin films by the chemical bath deposition(CBD)method is investigated,in which the films are first annealed in oxygen at a low temperature and then re-annealed in nitrogen at a higher temperature.It is shown that this process can effectively improve the optoelectronic properties of PbS thin films compared with pure oxygen annealing.Methods PbS thin films are fabricated on glass substrates by the CBD method.The reaction solution is composed of lead acetate[Pb(CH_(3)COO)_(2)·_(3)H_(2)O],trisodium citrate(C_(6)H_(5)Na_(3)O_(7)),potassium hydroxide(KOH),and thiourea(CH_(4)N_(2)S).The cleaned glass substrates are immersed in the deposition bath.After deposition,the samples are rinsed with deionized water and dried.The as-grown PbS films are uniform,mirror-reflective films,and subsequently,they are annealed in oxygen for 1 h at 550℃.Lastly,the oxygen-annealed thin films are re-annealed in nitrogen at 600℃for 10 min,50 min,80 min,and 110 min.The Cr/Au electrodes are realized by the magnetron sputter,and the phase and crystal structure of these samples are characterized by the X-ray diffractomet

关 键 词：薄膜 硫化铅薄膜 退火 化学浴沉积 响应度 比探测率 

分 类 号：TB43[一般工业技术]