Determination of temperature and light intensity on the Ni/chlorophyll-a/n-GaP device

Abstract

Based on the light absorption property of chlorophylls, chlorophyll-a molecules, the most abundant molecules of chlorophylls, were coated on the interfacial layer for a fabricated Ni/chlorophyll-a/n-GaP device. Current–voltage (I–V) measurements were assessed for different temperatures and levels of light intensity. The characteristic parameters of the device were calculated using different methods based on I–V measurements taken at room temperature. The Ni/chlorophyll-a/n-GaP device was subjected to I–V analysis for a temperature range of 80–300 K. The barrier height values increased with increasing temperature whereas ideality factor values decreased. The I–V characteristics of the device were examined under various light intensities at 300 K and the photovoltaic effects of the device were analyzed. The photocurrent value increased from 2.58 × 10−7 at 30 mW cm−2 to 5.46 × 10−7 at 100 mW cm−2, and the sensitivity value increased from 9.72 at 30 mW cm−2 to 18.83 at mW·cm−2, almost doubling. The results indicate that a chlorophyll-a layer has potential as a novel material for optoelectronic applications.