Recent progress of ZnMgO ultraviolet photodetector

Abstract

The ultra-violet (UV) detection has a wide application in both civil and military fields. ZnO is recognized as one of ideal materials for fabricating the UV photodetectors due to its plenty of advantages, such as wide bandgap, low cost, being environment-friendly, high radiation hardness, etc. Moreover, the alloying of ZnO with MgO to make ZnMgO could continually increase the band gap from ∼ 3.3 eV to ∼ 7.8 eV, which allows both solar blind and visible blind UV radiation to be detected. As is well known, ZnO is stabilized in the wurtzite structure, while MgO is stabilized in the rock salt structure. As a result, with increasing the Mg content, the crystal structure of ZnMgO alloy will change from wurtzite structure to rock salt structure. Therefore, ZnMgO photodetectors can be divided into three types based on the structures of alloys, namely, wurtzite-phase, cubic-phase and mixed-phase devices. In this paper, we review recent development and make the prospect of three types of ZnMgO UV photodetectors.

Broadband Detection Based on 2D Bi2Se3/ZnO Nanowire Heterojunction

“…With the morphology of one-dimensional nanowire arrays (NWAs), not only the space between the nanowire is well backed up for the strengthening of light trapping ability but also the superior transport properties provide the fast electron transport channel when making comparisons with its bulk and thin-film structures [16,17]. However, until now, the photoresponse performance of the ZnO nanowires UV detector is still lower than the theoretical predicted value, due to a large number of nonradiative centers at interface and electron trapped by the surface states [18].…”

Band structure regulation in Fe-doped MgZnO by initial magnetic moments

“…Thus, it is interesting and important to study the electronic and magnetic properties of ZnO-based DMS experimentally and theoretically, which have been seldomly reported. 13,14 With this consideration, herein, the rst-principle calculations are employed to study Fe-doped MgZnO. In 1Fe-doped MgZnO, the most stable conguration employed for further investigation was selected by determining the total energy, which is the lowest when the Fe atom occupies the second nearest site at the same A-face of the Mg atom.…”

Band tail state related photoluminescence and photoresponse of ZnMgO solid solution nanostructured films

“…The ZnMgO solid solution system is of interest due to the possibility to tailor many important physical properties by varying their composition. This alloy system covers a wide ultraviolet (UV) spectral range between the direct bandgaps of 3.36 eV for ZnO and 7.8 eV for MgO at room temperature, making it very attractive for short-wavelength optical applications such as UV detectors [1][2][3][4][5] and light emitters [6][7][8][9].…”

“…In terms of the crystal structure of ZnMgO films used in photodetectors, three types of structures are used, namely, hexagonal wurtzite structure (w-ZnMgO), cubic rock salt structure (c-ZnMgO) and films with mixed-phase (m-ZnMgO) [5]. Since the crystal structure of the alloy changes from w-ZnMgO to c-ZnMgO with increasing Mg content, the coexistence of two structures in ZnMgO films is unavoidable in the structure transformation process, in a certain interval of Mg concentrations.…”