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12 June 2001 Responsivity and gain in InGaAs/GaAs-QWIPs and GaAs/AlGaAs-QWIPs: a comparative study
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Proceedings Volume 4288, Photodetectors: Materials and Devices VI; (2001)
Event: Symposium on Integrated Optics, 2001, San Jose, CA, United States
We experimentally compare the peak responsivity R, gain g, quantum efficiency, and detectivity of GaAs/AlGaAs-QWIPs with devices based on the competing material system InGaAs/GaAs. For this purpose we use a typical n-type GaAs/AlGaAs-QWIP and three n-type InGaAs/GaAs-QWIPs with varying doping densities. R and g of the GaAs/AlGaAs-QWIP show a typical negative differential behavior, while both quantities grow monotonously with increasing bias voltage in the case of the InGaAs/GaAs-QWIPs. For identical nominal doping densities and similar cutoff wavelengths between 8.9 micrometers and 9 micrometers , InGaAs/GaAs-QWIPs show much higher responsivities than GaAs/AlGaAs-QWIPs. The ratio between these responsivities is 2.5 at the bias voltage where the GaAs/AlGaAs-QWIP has its maximum. By making use of the different bias dependence of the responsivity in both types of QWIPs a further enhancement of this factor is achieved. Nevertheless, both types of QWIPs show comparable detectivities. This is due to the fact that the gain has a negligible influence on the detectivity. In conclusion, InGaAs/GaAs-QWIPs are promising if high responsivities and short integration times are required.
© (2001) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Robert Rehm, Harald Schneider, K. Schwarz, Martin Walther, Peter Koidl, and Guenter Weimann "Responsivity and gain in InGaAs/GaAs-QWIPs and GaAs/AlGaAs-QWIPs: a comparative study", Proc. SPIE 4288, Photodetectors: Materials and Devices VI, (12 June 2001);

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