Design of Er_2O_3-capped SnO_2 nanostructures using glancing angle deposition technique for enhanced photodetection

摘要

Glancing angle deposition technique was employed to fabricate Er_2O_3-capped SnO_2 nanostructure on n-type Si substrate. The X-ray diffraction analysis depicts that the Er_2O_3-capped SnO_2 nanostructure was polycrystalline in nature. Higher pho-toluminescence intensity was obtained for Er_2O_3-capped SnO_2 nanostructure as compared to bare SnO_2 nanowires, due to the higher junction area between two layers and higher electron-hole pair generation. The photodetectors fabricated using Er_2O_3-capped SnO_2 nanostructure showed averagely 2.3 times higher photoresponse as compared to bare SnO_2 nanowire photodetector at -2 V. The enhanced photoresponse for Er_2O_3-capped SnO_2 nanostructure was described with reference to the interface junction. A high responsivity of 16.43 AAV and high detectivity of 2.58 × 10~(12) jones with noise equivalent power as low as 1.085 × 10~(12) W were obtained for Er_2O_3-capped SnO_2 nanostructure. Moreover, the current conduction mechanism of Er_2O_3-capped SnO_2 nanostructure was explained with the help of the band diagram.