Tang Ke

Photoresponse Properties of an n-ZnS/p-Si Heterojunction

An n-ZnS/p-Si heterojunction was fabricated by using the rf magnetron sputtering method. The band gap of the ZnS film is about 3.63 eV. Current-voltage (I—V) characteristics of the ZnS/Si heterojunction are examined and the results show the distinct rectifying characteristics with a turn-on voltage of about 1.8V. The UV (330 nm) and visible (450 nm) photoresponse properties of the heterojunction are also investigated, which demonstrates the potential of such an n-ZnS/p-Si heterojunction for detecting both UV and visible light.

Preparation of ZnO Thin Films on Free-Standing Diamond Substrates

Highly c-axis-oriented ZnO films were deposited successfully on the nucleation sides of free-standing diamond (FD) films by the direct current (DC) magnetron sputtering method. The effect of the sputtering parameters, such as power, gas pressure and sputtering plasma composition of Ar-to-O2, on the properties of ZnO thin films was investigated in detail. X-ray diffraction (XRD) measurements showed that, at a sputtering power of 200 W, gas pressure of 0.5 Pa and an Ar-to-O2 composition of 1:1, a higher intensity of the (002) diffraction peak and a narrower full width at half maximum (FWHM) were detected which meant high c-axis orientation and high quality of the ZnO films. To improve the quality of the ZnO film, a thin ZnO layer was pre-grown as a homo-buffer layer. XRD measurements showed that this buffer layer had a beneficial effect on the structural and morphological properties of the post-grown ZnO film.