ZnCdSe/ZnCdMgSe quantum well infrared photodetector

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Quantum Well Infrared Photodetectors (QWIPs) are crucial for infrared detection.
• II-VI semiconductor materials offer alternative properties for photodetector applications.
• Optimizing QWIP performance requires careful material design and fabrication.

Purpose of the Study:

• To design, fabricate, and characterize a II-VI ZnCdSe-based QWIP.
• To investigate the bound to quasi-bound transition for infrared detection at 8.7 µm.
• To evaluate the device's performance in terms of temperature dependence and responsivity.

Main Methods:

• Epitaxial growth of ZnCdSe/ZnCdMgSe quantum wells.
• X-ray diffraction for assessing epitaxial layer quality.
• Absorption and photocurrent measurements to characterize device performance.
• Temperature-dependent and bias-dependent photocurrent analysis.

Main Results:

• Successful fabrication of a II-VI QWIP with a bound to quasi-bound transition at 8.7 µm.
• Epitaxial layer quality confirmed by X-ray diffraction.
• Photocurrent exhibits exponential decrease with temperature and a significant increase with applied bias (over 4 orders of magnitude).
• Achieved operating temperature of 140K with a responsivity of 1-10 µA/W by optimizing bias.

Conclusions:

• The II-VI ZnCdSe-based QWIP demonstrates performance comparable to conventional III-V QWIPs.
• The device's temperature sensitivity can be effectively compensated by increasing the applied bias.
• This work highlights the potential of II-VI materials for advanced infrared photodetector applications.