An organic photodetector (PD) is fabricated with single layer thin film of copper phthalocyanine (CuPc) on glass substrate. The thermal deposition of CuPc film on the substrate was realized under high vacuum and at different substrate temperature (room temperature, 40 ◦C, 70 ◦C, 100 ◦C). The comparison of photoresponse characteristics of CuPc thin film deposited under different conditions showed good improvement with increase in the substrate temperature, and the best performances being observed for the film deposited at substrate temperature of 100 ◦C. The thin film of CuPc characterized through X-ray diffraction (XRD) spectroscopy and atomic force microscopy (AFM) clearly indicated that with increase in substrate temperature, the grain size of CuPc film increased, which improved the crystallinity and hence the photoconductivity of the device. The CuPc thin film based PD displayed stable and reproducible photoswitching characteristics under white light irradiation, with photocurrent modulation by varying in input optical power. The highest photo to dark current ratio and responsitivity of the devices was calculated to be, ca. 6.5 and 7.1 mA-W−1 at low optical power, ca. 14.5 mW-cm−2.
Conversion of YBCO Pellet into Single Layer Thin Film using Pulse Laser Deposition
