Accuracy of activation energy from Arrhenius plots and temperature-dependent internal photoemission spectroscopy

Abstract

In this work, the activation energy obtained from the temperature dependent internal photoemission spectroscopy (TDIPS) and thermionic dark currents using GaAs/AlGaAs photodetectors are compared. Different barrier heights within the p-type GaAs/AlGaAs heterostructures are studied. The temperature dependent spectral response shows the red-shifting of the detector threshold wavelength for increasing temperature due to the decreasing band-offset. The activation energy extracted from Arrhenius plot of the dark current-voltage-temperature (I-V-T), and measured spectral response show the carrier activation energy increases with increasing Al mole fraction and decreases with increasing doping density. For Infrared detectors with ≤ 6.5 m, the Arrhenius analysis yields the values of activation energy with less than 5 % deviation from the actual or TDIPS fitting values. However, for detectors with longer threshold wavelengths (>> λ.3 m), activation energy extracted from the Arrhenius plot leads to energy values which deviate more than ~ 10 % from the corresponding TDIPS values. The higher percentage deviation (>> 10 %) of activation energy determined by Arrhenius plot from the corresponding TDIPS values attribute to the temperature dependent Fermi distribution tailing effect and Fowler-Nordheim tunneling current.

Broadband and photovoltaic THz/IR response in the GaAs-based ratchet photodetector

“…To further clarify the hot-cold hole energy transfer mechanism, the activation energy of the detector (Δ) is obtained by the Arrhenius fitting based on the current-voltage-temperature ( I - V - T ) data ( 43 ), as shown in Fig. 2G .…”