两端叠层结构的中长波量子阱红外探测器  

Dual-band quantum well infrared photodetectors with two ohmic contacts

作　　者：霍永恒[1] 马文全[1] 张艳华[1] 黄建亮[1] 卫炀[1] 崔凯[1] 陈良惠[1] 

机构地区：[1]中国科学院半导体研究所纳米光电子实验室,北京100083

出　　处：《物理学报》2011年第9期740-745,共6页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(973项目)(批准号:2010CB327602)资助的课题~~

摘　　要：采用分子束外延技术生长了两个叠层结构的双色量子阱红外探测器结构,并经过光刻和湿法刻蚀制作成两端结构的量子阱红外探测器单元器件.通过改变量子阱势垒高度,势阱宽度,掺杂浓度,重复周期数等器件参数,可以使总电压在两个叠层之间产生适当的分布,从而使器件表现出不同的电压响应特点.光电流谱测量显示,器件1随着外加偏置电压可实现对于中波大气红外窗口(3—5μm)和长波大气红外窗口(8—12μm)红外响应的切换,器件2在不同的偏置电压下可以对这两个波段同时做出响应.本文探讨了两端叠层结构量子阱红外探测器的工作原理,将其归结为探测器光导增益随偏置电压增大先增大后减小的变化,以及总外加偏置电压在两个多量子阱层之间的不同分布,重点对于器件1的电压调制特征进行了分析.同每个单元器件制作三个电极的三端结构相比,两端结构能够使双色量子阱红外探测器的器件工艺大为简化,并且无需制作专门的双色读出电路,从而可以降低成本,并能提高面阵器件的填充因子.Two-color quantum well infrared photodetectors （QWIPs） with two stacks of QW series have been grown by molecular beam epitaxy and processed into mesa structure devices with only two ohmic contacts by photolithography and wet chemical etching. By changing QWIP parameters, including barrier height, well width, doping level and period number, the total bias voltage can be distributed to the two stacks in such a way that the stacked structure will show different photoresponse characteristics. The photocurrent spectrum measurements demonstrate that sample 1 can work alternately between the two atmospheric windows of 3—5 μm and 8—12 μm by tuning the voltage, while sample 2 can photorespond simultaneously to the irradiation of the two atmospheric windows. In this paper, the physics behind the two-contact type of QWIP is discussed. The voltage tunability and the simultaneous photoresponse are attributed to the change of photoconductive gain with the bias voltage and the distribution of the total bias between the two series. We here focus the discussion on the voltage tunability of sample 1. Compared with the three-contact-per-pixel structure, two-contact-per-pixel structure can greatly facilitate the dual-band focal plane array （FPA） device fabrication and increase the FPA fill factor.

关 键 词：电压调制 同时响应 量子阱红外探测器 双波段 

分 类 号：TN215[电子电信—物理电子学]