On the Stability of Amorphous Silicon Temperature Sensors

This article investigates the stability of hydrogenated amorphous silicon (a-Si:H) p-i-n junctions employed as temperature sensors in lab-on-chip (LoC) applications. The devices have been tested under forward current injection and different temperatures (from room temperature up to 90 degrees C) in order to reproduce the practical operating conditions. Two sets of devices with different diborane concentrations in the p-doped layer have been investigated as a case study. For both sets, a temperature-drift error of 0.05 degrees C/h and a sensitivity around 3 mV/degrees C in the range between 30 degrees C and 90 degrees C have been achieved. These results demonstrate the device suitability as a thin-film temperature sensor integrated into LoC systems that implement thermal treatment of the biological samples as, for example, DNA amplification.