Passivation of MWIR Heterostructure p-InAsSbP/n-InAs Photodiodes Using SiO2 Layers for Near-Room-Temperature Operation

We examined the effect of SiO2 passivation on the parameters of mesa heterostructure InAs/InAsSbP photodiodes with a spectral responsivity 50% cut off at 3.5 µm at 295 K, specific to the InAs absorber layer. The R0A product was found to increase by 30% after passivation of the devices of 113 µm in diameter, up to 0.9 Ωcm2, while for those with a diameter of 1.13 mm, R0A of 2.2 Ωcm2 was achieved, with a value of D* > 3 × 109 cmHz1/2/W at the peak of the spectrum, 1 kHz, 0 V bias, 295 K. To the best of our knowledge, this is the highest R0A value at room temperature reported to date for a photodiode with an InAs absorber.