InGaAsN metal-semiconductor-metal photodetectors with Modulation-doped heterostructures

InGaAsN metal-semiconductor-metal (MSM) photodetectors (PDs) with modulation-doped heterostructures have been successfully fabricated. It was found from capacitance-voltage measurements that carriers were well confined. Using thermionic emission theory and measured dark currents, it was found that effective Schottky barrier heights were 0.61, 0.72, 0.50, and 0.23 eV for the MSM-PDs with Al
_0.2
Ga
_0.8
As cap layer doping N
_d
=5times10
¹⁶
, 9times10
¹⁶
, 2times10
¹⁷
, and 6times10
¹⁷
cm
^-3
, respectively. Furthermore, it was found that measured responsivities were 0.02, 0.14, and 0.22 A/W and for the MSM-PDs with N
_d
=5times10
¹⁶
, 9times10
¹⁶
, and 2times10
¹⁷
cm
^-3
, respectively