Abstract
SrTiO 3 (STO) thin film has been fabricated on fused-quartz wafer by radio-frequency magnetron sputtering. The Ag interdigited electrodes were then evaporated on STO thin film in order to form the metal-insulator-metal photoconductive detector. Our photodetector exhibits a high photoresponse in the range of 225-340 nm with an ultraviolet-visible rejection ratio (R310 nm/R400 nm) of two orders of magnitude, indicating an intrinsic characteristic of visible-blindness. The maximum photocurrent responsivity is about 105 mA/W measured at 310 nm and the corresponding quantum efficiency is 42.1%. The dark current is only 0.4 nA at 50 V bias. Furthermore, the STO thin film detector presents a transient photovoltaic signal with a rise time of ∼330 ps and a fall time of ∼480 ps under the excitation of a 355-nm-pulsed laser, suggesting an ultrafast response characteristic of our STO thin film detector.
| Original language | English |
|---|---|
| Article number | 6203351 |
| Pages (from-to) | 2561-2564 |
| Number of pages | 4 |
| Journal | IEEE Sensors Journal |
| Volume | 12 |
| Issue number | 8 |
| DOIs | |
| State | Published - 2012 |
| Externally published | Yes |
Funding
Manuscript received December 11, 2011; revised March 2, 2012; accepted April 12, 2012. Date of publication May 21, 2012; date of current version June 6, 2012. This work was supported in part by the Open Foundation of the National Laboratory of Mineral Materials, China University of Geosciences, Beijing, under Grant 09A004, the National Natural Science Foundation of China under Grant 11104255, the Fundamental Research Funds for the Central Universities under Grant 2010ZY50 and Grant 2011YXL060, and the Open Foundation of the Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences. The associate editor coordinating the review of this paper and approving it for publication was Prof. Julian C. C. Chan.
Keywords
- Photodetector
- SrTiO thin film
- responsivity
