Self-powered adjustable UV and NIR photodetectors based on one-step synthesized TeO2 doped ZnO composite nanorods/Si heterojunction.

[Display omitted] • TZO CNRs with controllable morphology and composition through a traditional metal assisted CVD technique were fabricated. • Three self-powered photodetectors were fabricated using TZO CNRs/Si heterojunction which could detect UV-NIR selectively. • IV-characteristics on illumination of UV and/or NIR radiation show good and fast response. Tellurium dioxide (TeO 2) doped zinc oxide (ZnO) composite nanorods (TZO CNRs) were first synthesized by chemical vapor deposition method on a p-type silicon substrate covered by a sputtered gold (Au) film. The morphologies, structures, compositions and optical properties of the TZO CNRs can be modulated with the TeO 2 content. Three typical self-powered TZO CNRs/Si heterojunction photodetectors named device 1, 2 and 3 according to the different TeO 2 contents and TZO CNR morphologies are designed. Device 1 based on 1.81 At% Te content TZO CNRs can detect UV lights with wavelength from 290 to 380 nm and showed a responsivity of 4.3 mA/W, a detectivity of 1.1 × 1012 cmHz1/2W−1 upon exposure to 370 nm light at a zero-bias voltage. Device 2 based on 5.86 At% Te content TZO CNRs is found to be selectively sensitive to UV and NIR lights. Device 3 based on 9.23 At% Te content TZO CNRs is found to be also selectively sensitive to NIR lights. Its most sensitive wavelength is 1040 nm with responsivity and detectivity of 24.6 mA/W and 4.12 × 1012 cmHz1/2W−1, respectively. In addition, the mechanism that led to their typical properties of these devices are also elucidated. [ABSTRACT FROM AUTHOR]