Band alignment and interfacial structure of ZnO/Si heterojunction with Al2O3 and HfO2 as interlayers

Abstract

Electroluminescence behavior of ZnO/Si heterojunctions: Energy band alignment and interfacial microstructure

The function of a 60-nm-thick AlN buffer layer in n-ZnO/AlN/p-Si(111)

“…Figure 5 a shows the VBM and the CL spectra of Si 2 s recorded on Si substrate. The VBM of bulk Si was determined to be 0.15 eV by linear extrapolation, and the Si 2 s peak was located at 150.18 eV corresponding to the Si-Si bond [ 16 ]. The Zn 2p 3/2 and Si 2 s spectra at the interface of ZnO/Si heterojunction were presented in Figure 5 b, and the peaks were located at 150.07 and 1022.26 eV, respectively.…”

“…It is well know that in the system of n-ZnO/p-Si, electron and hole recombination takes place mainly in Si rather than in ZnO, leading to a difficult application for lighting since Si has a narrow and indirect band gap. Owing to the difference in band gaps between ZnO and Si that provides an effective electron injection from ZnO to p-Si and blocks the flow of holes from p-Si to ZnO [ 16 ], it is necessary to understand the physical properties of the ZnO/Si heterojunction, especially the energy band alignment and interfacial microstructure. Some researchers employed different dielectric buffer layers to study the band alignment of the ZnO/p-Si heterojunction [ 16 - 18 ].…”

“…Owing to the difference in band gaps between ZnO and Si that provides an effective electron injection from ZnO to p-Si and blocks the flow of holes from p-Si to ZnO [ 16 ], it is necessary to understand the physical properties of the ZnO/Si heterojunction, especially the energy band alignment and interfacial microstructure. Some researchers employed different dielectric buffer layers to study the band alignment of the ZnO/p-Si heterojunction [ 16 - 18 ]. However, few reports mentioned AlN buffer layers between ZnO and Si.…”

“…In this work, AlN buffer layer was introduced and the valence band offset (VBO) of ZnO/Si heterojunction was modified from 3.06 to 3.78 eV while the VBO between AlN and Si substrate was 2.95 eV. It was reported that the presence of SiO x made the VBO between SiO x and Si to be 3.15 eV [ 17 ], and those of Al 2 O 3 and HfO 2 between ZnO and Si substrate made the VBOs to be 3.24 and 2.87 eV, respectively [ 16 ].…”

~3-nm ZnO Nanoislands Deposition and Application in Charge Trapping Memory Grown by Single ALD Step

“…10 based on the XPS measurements and reported values of the band offsets and bandgaps of the different materials434445. Therefore, during the program operation when a negative gate voltage is applied, the electrons in V O and V O + states gain enough energy and get emitted to the channel while holes in the channel gain enough energy and tunnel through the tunnel oxide and get trapped within the deep quantum well formed by the valence band offsets.…”