Solution Processable P3HT/CdS Photodiodes and Their Electrical Characterization

Abstract

In this work we apply simple layer solution deposition methods for the assembling of CdS/P3HT (poly(3-hexylthiophene)) p-n heterostructures and analyzed their photodetection properties in the visible optical range. The CdS-n layers were deposited on ITO-coated glass substrates by the chemical bath method employing an ammonia-free recipe. The P3HT-p layers were deposited on the CdS/ITO/glass substrates by the casting method from solution by dissolving P3HT in chloroform. As the back electrodes, to complete the p-n heterostructures, carbon (graphite) was used. The electrical properties of the assembled CdS/P3HT hybrid photodiodes in dark and under illumination at several intensities, in the 0-100 mW/cm 2 interval, were analyzed from current density versus voltage (J-V) measurements, in the-5V to 5V bias voltage range. From these measurements, the photosensitivity of the photodiodes as a function of bias voltage was determined as 370 mA/W. The response of the photodiodes as a function of illumination intensity was determined from transient photocurrent measurements.

Solution-based CdS thin film transistors with low temperature-processed Al2O3-GPTMS-PMMA as hybrid dielectric gate

“…In particular, in our group, we have reported a convenient ammonia-free CBD process to achieve CdS thin films [18,19], which have performed very well as window layers in solar cells, as well as active channels in TFTs employing organic (polyvinyl phenol-PVP), inorganic (SiO 2 and HfO 2 ) and hybrid (PVP-SiO 2 and PVP-TiO 2 ) dielectric gate layers [20][21][22][23]. We have also found that this CBD process can be photoactivated with UV light enabling the chemical deposition of CdS films at room temperature [22][23][24].…”