Frequency response and carrier escape time of InGaAs quantum well-dots photodiode

作者：A. E. Zhukov, S. A. Blokhin, N. A. Maleev, N. V. Kryzhanovskaya, E. I. Moiseev, A. M. Nadtochiy, S. А. Mintairov, N. А. Kalyuzhnyy, F. I. Zubov, M. V. Maximov · 发表于：Optics Express · 年份：2021 · DOI：10.1364/oe.441693 · 被引用次数：5 · 研究领域：Semiconductor Quantum Structures and Devices、Semiconductor Lasers and Optical Devices、Photonic and Optical Devices

p-i-n photodiodes comprising dense arrays of InGaAs quantum dots (referred to as quantum well-dots) were fabricated, and the basic physical processes affecting their high-speed performance were studied for the first time by measuring the frequency response under illumination with photons absorbed either in the quantum well-dots (905-nm illumination) or mainly in GaAs layers (860-nm illumination). A GaAs p-i-n photodiode of similar design was also measured for comparison. A maximum −3 dB bandwidth of 8.2 GHz was measured for the 905-nm light illumination, and maximum internal −3 dB bandwidth of 12.5 GHz was estimated taking into account the effect of RC-parasitic by the equivalent circuit model. It was found that the internal response is mainly controlled by the carrier drift time in the depletion region; this process can be characterized by a field-dependent effective velocity of charge carriers in the layered heterostructure, which is approximately half the saturation velocity in GaAs. The carrier escape from the InGaAs quantum well-dots was found to has less effect; the escape time was estimated to be 12–17 ps depending on the reverse-bias voltage applied.