Modeling of electrical and optical characteristics of near room-temperature CdS/ZnSe based NIR photodetectors

• We model the electrical and optical characteristics of (CdS/ZnSe)/BeTe QWIP near 300 K.
• This system is used for the first time in such application.
• The simulation takes into account three mechanisms of carrier transport: G–R, Diff and TAT processes.
• The investigations have been performed over a wide range of temperatures and bias voltages.
• For 1.55 μm cutoff wavelength, D* ∼ 5.7 × 1010 cm Hz1/2/W has been achieved in X BeTe minimum.

Results of modeled photodetector characteristics in (CdS/ZnSe)/BeTe multi-well diode with p–i–n polarity are reported. The dark current density (J–V) characteristics, the temperature dependence of zero-bias resistance area product (R0A), the dynamic resistance as well as bias dependent dynamic resistance (Rd) and have been analyzed to investigate the mechanisms limiting the electrical performance of the modeled photodetectors. The quantum efficiency, the responsivity and the detectivity have been also studied as function of the operating wavelength. The suitability of the modeled photodetector is demonstrated by its feasibility of achieving good device performance near room temperature operating at 1.55 μm wavelength required for photodetection in optical communication. Quantum efficiency of ∼95%, responsivity ∼0.6 A/W and D* ∼ 5.7 × 1010 cm Hz1/2/W have been achieved at 300 K in X BeTe conduction band minimum.