Abstract
In this article, the photoelectric behavior of sandwich type
n-GaAs/orange dye, vinyl-ethynyl-trimethyl-piperidole/conductive glass sensors was investigated. Devices were fabricated by employing electrodes of heavily doped (2
×
10
18 cm
−
3
)
n-type GaAs and conductive glass of In
2O
3, whereas the electrolyte was a mixture of orange dye (OD) and vinyl-ethynyl-trimethyl-piperidole (VETP). Dark current voltage (
I–
V) characteristics of the devices exhibited small rectification behavior with zero offset voltage, which shows the presence of electrochemical effects in the devices. Photo-induced alternating and direct open-circuit voltages and short-circuit currents were investigated by using infra-red, red, green and blue light sources, and it was observed that the devices were sensitive to the wavelengths ranging 550 nm–700 nm. Based on the observed optical spectra of OD-VETP electrolyte and GaAs a plausible band diagram of the device was developed to explain the observed
I–
V characteristics and to draw its equivalent circuit diagram.