Modeling and analysis of the spectral response for AlGaAs/GaAs HPTs for short wavelength optical communication

Abstract

Detailed spectral response (SR) modeling for heterojunction bipolar phototransistors (HPTs) is presented in this work. All the related physical parameters are taken into account for the resolution of photogenerated excess minority carrier continuity equations in the active layers of the HPT. The layer dependence of the optical flux absorption profile at near-bandgap wavelengths is also investigated and its generalization as a single-exponential has been refuted for HPTs based on GaAs material systems (InGaP-GaAs/AlGaAs-GaAs). The variation in the responsivity of the device with changing base width is analyzed at various wavelengths and a detailed experimental setup for optical characterization of HPTs is also provided. The measured results at 635, 780, 808, and 850 nm show good agreement to the modeled data, validating the newly developed theoretical model. V

Investigation of optically generated kink effect in GaAs-based heterojunction phototransistors

“…The micrograph of fabricated device is given in Figure 1 and the absorption area is 1.75 × 10 3 μm 2 . The detailed experimental set up can be found elsewhere [18]. Both the collector and the base currents saturate at the same level, and the gain in this region is unity.…”

Model characterization of heterojunction bipolar transistor InP/InGaAs optoelectronic mixer

“…To be more specific, the InP/InGaAs HBTs have been used especially in optoelectronic circuits for 1550 nm fiber optic communications. In such application, HBT proves to be a better choice than other devices such as HEMT and GaAs FETs [13] when implemented as an OEM. This is mainly because it can reduce phase noise after the optical injection matches with the injection of an optical signal which has been previously modulated at the oscillation frequency.…”

Comparative Study of Si-Ge-Sn Resonant Cavity Enhanced Heterojunction Bipolar Phototransistor (RCE-HPT) under Quantum Confined Stark Effect (QCSE) and Franz Keldysh Effect (FKE) at 1.55 µm

“…It is a strong competitor of p-i-n and APD due to its inherent gain and absence of excess noise. A number of researchers have reported the characteristics of HPT based on III-V compounds and their alloys [28][29][30][31][32] and group-IV compounds [23][24][25][26][27]. Basu et al [23] have reported their study on HPT based on GeSn, which shows that GeSn based HPT can compete with InGaAs based devices.…”