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. Cur-rent-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 x 10-7 at 30 mW cm-2 to 5.46 x 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 & sdot;cm- 2, almost doubling. The results indicate that a chlorophyll-a layer has potential as a novel material for optoelectronic applications.