The effect of measurements and layer coating homogeneity of AB on the Al/AB/p-Si devices

Abstract

Aniline blue (AB) thin film layers were deposited on p-Si and glass substrates by spin coating technique to investigate measurements and layer coating homogeneity effect on the properties of the Al/AB/p-Si devices. While the AB thin film layers on the glass substrates were employed for absorption measurements, the AB layer on the Si substrates were used as interlayer for the Al/p-Si devices by hole array mask. The used organic AB thin film layers were obtained by the same experimental parameters and two substrate samples on glass and Si substrates were named as first and second substrate samples. Randomly preferred nine Al/AB/p-Si devices at the first Si sample and seven Al/AB/p-Si devices at the second Si sample were studied and compared in details. The UV–Vis spectrometer, I–V and C–V measurements were performed on the substrate samples at room temperature. The absorption spectra of the samples confirmed that the AB layers were successfully deposited on the substrates. The device parameters such as saturation current, ideality factor (n), barrier height (Φb) and series resistance were extracted from the I–V measurements and compared for various devices at the first and second substrate samples. In addition, the photodiode property of the randomly preferred one of the Al/AB/p-Si device was investigated by the I–V measurements under dark and light illumination conditions. The result approved photodiode property of the Al/AB/p-Si devices. The C–V and G-V measurements were utilized on the randomly preferred one device from the first and one from second substrate samples for various frequencies, and the various electrical parameters were calculated and discussed. The characterization results revealed that the measurements errors and layer coating homogeneity affect the device properties. Furthermore, the Al/AB/p-Si devices can be used as photodiode, rectifier and capacitor at room temperature.