Extraction of minority carrier diffusion length of MWIR Type-II superlattice nBp detector
| Autor: | Vincent M. Cowan, Christian P. Morath, Priyalal S. Wijewarnasuriya, Gamini Ariyawansa, Stephen Myers, Sanjay Krishna, Alireza Kazemi, Sen Mathews, Elizabeth H. Steenbergen, John E. Scheihing, Zahra Taghipour |
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| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Physics business.industry Superlattice Detector 02 engineering and technology Carrier lifetime Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology 01 natural sciences Molecular physics Wavelength Attenuation coefficient 0103 physical sciences Optoelectronics Quantum efficiency Diffusion (business) 0210 nano-technology business Dark current |
| Zdroj: | Infrared Sensors, Devices, and Applications VII. |
| DOI: | 10.1117/12.2274591 |
| Popis: | We present a model for the spectral external quantum efficiency (EQE) to extract the minority carrier diffusion length (Ln) of a unipolar nBp InAs/GaSb Type-II superlattice (T2SL) mid-wave infrared (MWIR) detector. The detector consists of a 4 μm thick p-doped 10ML InAs/10ML GaSb SL absorber with a 50% cut-off wavelength of 5 μm at 80 K and zero bias. The n-type doped InAs/AlSb SL barrier in the structure was included to reduce the GR dark current. By fitting the experimentally measured EQE data to the theoretically calculated QE based on the solution of the drift-diffusion equation, the p-type absorber was found the have Ln = 10 ± 0.5 μm at 80K, and Ln = 12 ± 0.5 μm at 120K and 150K. We performed the absorption coefficient measurement at different temperatures of interest. Also, we estimated the reduced background concentration and the built-in potential by utilizing a capacitance-voltage measurement technique. We used time-resolved-photoluminescence (TRPL) to determine the lifetime at 80K. With the result of the model and the lifetime measurement, we calculated the diffusion coefficient and the mobility in the T2SL detector at various temperatures. Also, we studied the behavior of different dark current mechanisms by fitting the experimentally measured and simulated dark current density under different operating temperatures and biases. |
| Databáze: | OpenAIRE |
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