Comparison of Performance of Integrated Photodetectors Based on ZnS and ZnSe Metal–Semiconductor–Metal Photodiodes

The successful fabrication of monolithically integrated photodetectors composed of a heterojunction bipolar transistor (HBT) and a metal-semiconductor-metal (MSM) photodiode was achieved by a patterned oxide growth technique The photoresponsivities of the ZnS and the ZnSe MSM photodiodes were 0028 and 0.08A/W. respectively. Comparison of the performance in terms of optical and electrical characteristics between the ZnS- and the ZnSe-based integrated photodetectors were carried out; at a bias of 5 V, the current amplification ratios were 18,2 and 20 8. respectively The maximal measurable input optical power intensities were 273 mu W for ZnS-based integrated photodetector and 94 mu W for ZnSe-based integrated photodetector. This successful integration indicates the potential of the patterned oxide growth technique in the development of integrated devices based on II-VI ZnS and ZnSe compounds for short-wavelength applications (C) 2009 The Japan Society of Applied Physics