Near-room temperature MWIR HgCdTe photodiodes limited by vacancies and dislocations related to Shockley–Read–Hall centres

• Published in: Solid-state electronics Vol. 63; no. 1; pp. 8 - 13
• Main Authors: Jóźwikowski, K., Kopytko, M., Piotrowski, J., Jóźwikowska, A., Orman, Z., Rogalski, A.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.09.2011; Elsevier
• Subjects: Applied sciences; Cadmium compounds; Compound structure devices; Design. Technologies. Operation analysis. Testing; Dislocations; Electronics; Exact sciences and technology; HgCdTe heterostructures; Integrated circuits; Intermetallics; Mercury compounds; Misfit dislocations; Optoelectronic devices; Photodiodes; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Tellurides; Thermal generation; Trap-assisted tunnelling; Tunnelling; Uncooled photodetectors; Vacancies; Uncooled photodetectors; Trap-assisted tunnelling; Misfit dislocations; Thermal generation; HgCdTe heterostructures; Ternary compound; Voltage current curve; Thermal management (packaging); Charge carrier; Tunnel effect; Dislocation density; Far infrared radiation; Misfit dislocation; Cadmium tellurides; Optoelectronic device; Mercury tellurides; Activation energy; Cooling; II-VI compound; Vacancy; Absorber; Trap; Photodiode; Photodetector; Charge carrier trapping; Cooling system; Mercury; Heterostructures; Room temperature
• ISSN: 0038-1101; 1879-2405
• DOI: 10.1016/j.sse.2011.05.030

► I– V characteristics of uncooled photodetectors are investigated. ► Trap assisted tunnelling is considered as the mechanisms enhanced thermal generation. ► Traps are located at dislocation cores and mercury vacancies. ► Misfit dislocations are occurred at graded gap interfaces of HgCdTe heterostructures. Trap assisted tunnelling via traps located at dislocation cores as well as mercury vacancies are considered as the mechanisms of enhanced thermal generation of charge carriers in reverse-biased MWIR HgCdTe photodiodes operating with Peltier cooling. Field-induced reduction of trap activation energies increases thermal generation and creates conditions for large tunnelling currents. The model for LWIR devices published previously in Ref. [20], also explain experimental current–voltage characteristics of the MWIR photodiodes assuming great misfit dislocation density at graded gap interfaces between absorber and contact regions.