纳米硒的制备及其光电性能

Optical and electrical performance of nano-Se and its preparation

以导电玻璃（ITO）为基底,采用电沉积法制备纳米硒。在单一变量的基础上结合正交试验和响应面试验,探讨了制备条件对纳米硒光电压的影响。结果表明：在沉积电压1.7 V、沉积温度30℃、沉积时间7 min、硫脲用量为1 mmol时,纳米硒的光电压值最高,达0.868 4 V;由紫外-可见吸收光谱测得其禁带宽度Eg=1.84 e V;SEM分析发现,纳米硒呈棒状及莲花状结构,棒直径约为100 nm,长度为3-6μm;XRD表征结果显示,纳米硒主要为3种晶系的混晶系纳米晶体,在2θ为37.188°、45.246°、60.324°处分别出现斜方晶系纳米硒的（120）、（200）和（211）晶面,在2θ为30.141°、50.701°处分别出现六方晶系纳米硒的〈101〉、{11-1}晶面,在2θ为35.522°处出现单斜晶系纳米硒的[120]晶面,其中以〈101〉晶面和[120]晶面为择优生长取向。

Based on the single variable test, the orthogonal experiment was used to investigate the influences of the preparation conditions on the photovoltage of the nano-Se electrodeposited on the the conductive glass （ITO） substrate. It shows that the photovoltage of the nano-Se reached the highest value of 0. 868 4 V with the deposition voltage of 1. 7 V, the deposition temperature of 30 ℃ , the deposition time of 7 min, and the amount of thiourea of lmmol. In the UV-visible absorption spectra, the width of the forbidden band gap of the nano-Se is 1. 84 eV. The scanning electron microscopy reveals rod-like structure and the diameter of the selenium nanorod is about 100 nm, the length is 3 - 6μm. The XRD results show that nano-selenium is a mixed crystal nanocrys-talline system mainly composed of three kinds of crystal system. The first is rhomboidal with nano-Se （120 ）, （200） and （ 211） crystal plane, at 2θ of 37. 188 ° , 45. 246 ° , 60. 324 The second one is hexagonal with nano-selenium 〈 101 〉,{11-1} plane, at 26 of 30. 141 ° , 50. 701 °. The third is monoclinic with[ 120] crystal plane at 2θ of 35. 522 g. The preferential growth occurs along the 〈 101 〉 crystal plane and the[ 120] crystal plane.