Abstract
In this paper, an N-I-dot-in-well-I-N photodetector is reported. It has a specific inner multiplication at extremely low bias voltages and extremely low dark current accompanied by high current gains. The current-voltage (I-V) test results show its responsivity exceeds 200 A/W at 633 nm and −2.5V lower bias. The photoelectric response spectrum of the photodetector shows excellent light absorption characteristic form 400 nm up to 850 nm. The dark current is lower than 0.02 pA at bias −2.25 V and 100 K. The S (signal)/N (noise) has reached 106 at 20 nw illumination light power. The high sensitivity features of the photodetector make it a promising choice for medical diagnosis, biomolecular Science and environmental protection.