基于p型半导体与n型半导体间的特殊p-n结效应可有效提高紫外探测器的紫外光敏性能,研究了高密度p型聚苯胺(PANI)纳米线阵列的制备方法,及其与n型单晶硅片组装为具有p-n结效应的高性能紫外探测器的方法.采用旋涂煅烧法在单晶硅片表面制备了二氧化锰层,研究了以其为种子层制备高密度聚苯胺纳米线阵列的方法,并考察了不同制备条件对聚苯胺形貌的影响,揭示了聚苯胺纳米线阵列的形成机理.结果表明,利用二氧化锰种子层对溶液中苯胺的氧化作用,可优先在二氧化锰层表面形成聚苯胺纳米粒子,然后再向溶液中加入另一氧化剂过硫酸铵(APS),可使聚苯胺纳米粒子沿垂直于衬底方向进一步生长,从而制得了分布均匀的高密度p型聚苯胺纳米线阵列.利用p型聚苯胺纳米线阵列与n型单晶硅片间特殊的p-n结效应,构筑了性能优良的紫外探测器,对紫外光响应速度快、恢复时间短、稳定性好.当外置偏压为0 V时,光电流可达9.2×10^-8A;且随外置偏压提高,光电流强度大大增强,当外置偏压提高至5 V时,光电流可达3.2×10-5A,比0 V时提高了约1000倍.
The purpose is to study the preparation of p type polyaniline( PANI) nanowire array and the fabrication of high performance UV photodetector with p-n junction based on p type polyaniline nanowire array and n type silicon. High-density polyaniline nanowire array was fabricated by using a layer of manganese dioxide as seed layer which was prepared by spin-coating method on the silicon substrate. The influence of different conditions on the morphology of polyaniline was discussed,and the growth mechanism of polyaniline nanowire array was revealed. It was found that polyaniline nanoparticles were priorly generated on the manganese dioxide seed layer with the oxidation of manganese dioxide seed layer to aniline in solution. The polyaniline nanoparticles grew vertically when another oxidant of ammonium persulfate( APS) was added into the solution,and high-density p type polyaniline nanowire array was obtained. Furthermore,high performance UV photodetector was fabricated with fast photoresponse,short recovery time and good stability based on the p-n junction of p type polyaniline nanowire array and n type silicon. When the bias voltage was 0 V,photocurrent was 9. 2 × 10- 8A. And the intensity of photocurrent increased greatly when the bias voltage was improved. When the bias voltage arrived at 5 V,the photocurrent was improved to 3. 2 × 10- 5A which was 1000 times higher than that with 0 V bias voltage.