基于硒化物层状材料的湿法刻蚀和光电特性研究

发布时间：2018-05-26 12:29

本文选题：金属硒化物 + 硒化铋　；参考：《电子科技大学》2015年硕士论文

【摘要】：硒化物层状材料具有独特的光学、电学特性,在薄膜太阳电池、热电器件等领域具有良好的应用前景,已引起学术和产业界的高度重视。本文研究了Bi2Se3(V-VI族)和In2Se3(III-VI族)为代表的硒化物的性质、制备方法及其应用。分别从硒化物层状材料的刻蚀以及材料的光学电学性能来探讨了硒化物层状材料的特性和发展。研究在Si(111)衬底上采用物理气相沉积(PVD)制备出单晶的Bi2Se3薄膜和分子束外延(MBE)的方法制备出单晶的In2Se3薄膜,重点研究了Bi2Se3材料的湿法刻蚀和单相In2Se3的光学特性。具体研究内容和结论如下:(1)研究了K2Cr2O7-H2SO4和K2Cr2O7-HCl两种不同刻蚀液对Bi2Se3薄膜的刻蚀作用效果和反应机理。虽然两种刻蚀液对Bi2Se3薄膜的刻蚀都有效果,但刻蚀出来的界面还是有很大的差别。H+浓度为12 mol/L的K2Cr2O7-H2SO4刻蚀液,刻蚀30秒后的界面存在许多大的直径在20 nm~300 nm之间的岛状物,而且其界面的粗糙度要高于K2Cr2O7-HCl刻蚀后的界面,这不能算是好的刻蚀界面;而H+浓度为8 mol/L的K2Cr2O7-HCl刻蚀液刻蚀30秒的界面平整光滑,虽然刻蚀之后的界面是一个富Bi的界面,但其横向刻蚀性能良好。它们的刻蚀速率在室温下均为120 nm/min。上述工作第一次系统的研究了Bi2Se3层状材料的刻蚀,为Bi2Se3硒化物薄膜在热电器件制备领域中的应用提供了参考。(2)研究了In2Se3薄膜的可控生长和基于In2Se3薄膜的光电器件的变温I-V特性和光电转换效率。我们过控制In2Se3薄膜生长的衬底温度,成功制备除了α-In2Se3单晶薄并利用XRD和SEM观测了其形貌;利用α-In2Se3单晶薄膜制备出了太阳能电池结构,并对该器件进行了外量子转换效率(EQE)的测量,尽管我们制作的太阳能器件没有做任何的抗反射图层或者吸收窗口,器件在可见光波段530 nm到880nm的范围内,EQE的值超过20%,而且它的光响应下降边缘达到880 nm。器件的面积为0.2 cm2,在1个标准太阳光强照射下(100 mW cm-2),器件的短路光电流密度(JSC),开路电压(VOC)和占空因数(ff)的值分别为:JSC=9.6 mA cm-2,VOC=247 mV and ff=32.3%,单位面积的光电转换效率达到了0.77%。结果表明,利用MBE技术制备的In2Se3-Si光电池达到了比较高的光电转化效率,同时表明了In2Se3薄膜在光电领域中具有巨大的发展潜力良好的应用前景。
[Abstract]:Because of its unique optical and electrical properties, selenide layered materials have a good application prospect in thin film solar cells, thermoelectric devices and so on, and have attracted great attention in academic and industry fields. In this paper, the properties, preparation methods and applications of selenides represented by Bi2Se3(V-VI family and In2Se3(III-VI family are studied. The properties and development of selenide layered materials were discussed from the etching of selenide layered materials and the optical electrical properties of the materials. Single crystal Bi2Se3 thin films and MBE thin films were prepared by physical Vapor deposition (PVD) on Si (111) substrates. The wet etching of Bi2Se3 materials and the optical properties of single-phase In2Se3 were studied. The specific contents and conclusions are as follows: (1) the etching effect and reaction mechanism of K2Cr2O7-H2SO4 and K2Cr2O7-HCl on Bi2Se3 thin films have been studied. Although the two kinds of etching solution have good effect on the etching of Bi2Se3 film, there is a great difference in the interface between the two kinds of etching solution. H concentration is 12 mol/L K2Cr2O7-H2SO4 etching solution. After 30 seconds of etching, there are many islands with large diameter between 20 nm~300 nm and 20 nm~300 nm at the interface. Moreover, the roughness of the interface is higher than that of the interface after K2Cr2O7-HCl etching, which is not a good etching interface, while the interface of K2Cr2O7-HCl etching solution with H concentration of 8 mol/L is smooth and smooth for 30 seconds, although the interface after etching is a Bi rich interface. But its transverse etching performance is good. Their etching rates are 120 nm / min at room temperature. For the first time, the etching of Bi2Se3 layered materials has been studied systematically. The controllable growth of Bi2Se3 thin films and the variable temperature I-V characteristics and photoelectric conversion efficiency of In2Se3 thin film based optoelectronic devices were studied. We have successfully prepared 伪 -In2Se3 single crystal thin films by controlling the substrate temperature of In2Se3 thin films and observed the morphology of 伪 -In2Se3 single crystal thin films by XRD and SEM, and prepared solar cell structure by 伪 -In2Se3 single crystal thin films. The external quantum conversion efficiency (EQE) has also been measured, even though the solar devices we have made do not have any anti-reflection layers or absorption windows. The EQE of the device is more than 20 in the range from 530nm to 880nm in the visible light band, and the decreasing edge of its optical response is up to 880nm. The area of the device is 0.2 cm ~ (-2). The short circuit photocurrent density (JSCC), open circuit voltage (VOC) and duty factor (f) of the device are respectively: 9. 6 mA ~ (- 2) m ~ (-2) VOC ~ (2) V and ff32. 3 ~ 3. The photoelectric conversion efficiency per unit area of the device is 0. 777mW / cm ~ (-2) and 0. 777mV / cm ~ (-2), respectively. The results show that the In2Se3-Si photocell fabricated by MBE technology has achieved high photoelectric conversion efficiency, and it also shows that In2Se3 thin films have great development potential in the field of optoelectronic applications.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304

【相似文献】