太赫兹量子阱探测器性能研究及提高  

Study on the performance and optimization of terahertz quantum-well photodetectors

作　　者：高继红[1] 贾敬岳 张月蘅[1] 沈文忠[1] 

机构地区：[1]上海交通大学物理与天文系,上海200240

出　　处：《红外与毫米波学报》2015年第6期731-736,共6页Journal of Infrared and Millimeter Waves

基　　金：国家自然科学基金(11074167;91221201;61234005);863计划(2011AA010205)~~

摘　　要：提出了一个砷化镓基(GaAs/Al_(0.04)Ga_(0.96)As)太赫兹量子阱探测器,并对其光电流谱和背景噪声限制温度进行了表征,得到峰值响应频率为6.78 THz,背景噪声限制温度为16 K.理论上,首先,考虑多体效应对器件能带结构的影响,计算得峰值响应频率为6.64 THz,考虑到制备过程中的误差(THz器件较中红外器件,铝组分低,阱宽窄),理论与实验吻合的较好,证实了多体效应在太赫兹量子阱探测器中的重要影响;然后,对器件的电流电压特性进行研究,计算得到背景噪声限制温度为17.5 K,与实验吻合.太赫兹量子阱探测器较低的工作温度,极大限制了其应用,提出了两种实现高温探测的方法:(1)引入光学汇聚天线,提高器件背景限制温度,计算结果表明当引入增强系数为10~6倍的天线时,其背景噪声限制温度达到97 K(远高于液氮温度77 K);(2)太赫兹量子阱探测器与太赫兹量子级联激光器联用,可实现信号噪声限制模式,从而实现高温探测.计算表明,当激光器功率达到0.003 mW/μm^2,器件的工作温度可达77K.A newly designed terahertz quantum-well photodetector（ THz QWP） sandwiched between GaAs and Al_（0. 04）Ga_（0. 96） As material was demonstrated. Experimentally,we measure the response photocurrent spectra and the current-voltage curve and obtain the peak response of 6. 78 THz and backgroundnoise-limited performance（ BLIP） temperature of 16 K. Theoretically,we investigated the many body effect to the band structure of THz QWP and calculate the peak response of 6. 64 THz which is in agreement with the experiment. So,many-body effect must be included in the design of THz QWPs. Then,we calculate the BLIP temperature of 17. 5 K which is fitted well with the measurement.However,the low BLIP temperature is the main factor limiting applications of THz QWPs; we propose two schemes to improve the operating temperatures. Firstly,a scheme using an optical antenna to increase the BLIP temperature is proposed. Calculation shows the device is expected to achieve BLIP at 76 K when employing a 10~6 enhancement antenna. The second scheme is to use a THz quantum cascade laser as signal source to achieve photon-noise-limited performance（ PLIP） at high temperatures.Simulations show that when the illumination intensity reaches 0. 01 mW/μm^2,the operation temperature could be 77 K.

关 键 词：太赫兹量子阱探测器 多体效应 高温探测 背景噪声限制 信号噪声限制 

分 类 号：O469[理学—凝聚态物理]