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

Wang W, Chen C, Zhang G, Wang T, Wu H, Liu Y, Liu C - Nanoscale Res Lett (2015)

Bottom Line: Meanwhile, the ZnO crystalline quality was significantly improved as verified by both XRD and PL analyses.The valence band offsets have been determined to be 3.06, 2.95, and 0.83 eV for ZnO/Si, ZnO/AlN, and AlN/Si heterojunctions, respectively, and the band alignment of ZnO/Si heterojunction was modified to be 0.72 eV after introducing the AlN buffer layer.Our work offered a potential way to fabricate Si-based ultraviolet light-emitting diodes and improve the device performances.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan, 430072 People's Republic of China.

ABSTRACT
ZnO films were prepared on p-Si (111) substrates by using atomic layer deposition. High-resolution x-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), photoluminescence (PL), and I-V measurements were carried out to characterize structural, electrical, and optical properties. After introducing a 60-nm-thick AlN buffer layer, the growth direction of the ZnO films was changed from [10] to [0002]. Meanwhile, the ZnO crystalline quality was significantly improved as verified by both XRD and PL analyses. It has been demonstrated that the reverse leakage current was greatly reduced with the AlN buffer layer. The valence band offsets have been determined to be 3.06, 2.95, and 0.83 eV for ZnO/Si, ZnO/AlN, and AlN/Si heterojunctions, respectively, and the band alignment of ZnO/Si heterojunction was modified to be 0.72 eV after introducing the AlN buffer layer. Our work offered a potential way to fabricate Si-based ultraviolet light-emitting diodes and improve the device performances.

No MeSH data available.


Related in: MedlinePlus

Cross-sectional SEM images of sample a and b.
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Fig2: Cross-sectional SEM images of sample a and b.

Mentions: The cross-sectional SEM images of samples A and B are shown in Figure 2. The irregular cross profile of sample A revealed a polycrystalline nature of the ZnO film grown without any buffer layer on Si. Figure 2b shows that the AlN buffer layer was introduced between the ZnO film and Si substrate, and the thickness of AlN buffer layer was measured to be 60 nm. It is obvious that the ZnO films in Figure 2b was regularly oriented while it was rambled in Figure 2a. The number of stacking faults and edge dislocations of sample B were obviously less than that of sample A. It can be concluded that with the AlN buffer layer, the crystalline quality of ZnO films was significantly improved.Figure 2


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

Wang W, Chen C, Zhang G, Wang T, Wu H, Liu Y, Liu C - Nanoscale Res Lett (2015)

Cross-sectional SEM images of sample a and b.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385121&req=5

Fig2: Cross-sectional SEM images of sample a and b.
Mentions: The cross-sectional SEM images of samples A and B are shown in Figure 2. The irregular cross profile of sample A revealed a polycrystalline nature of the ZnO film grown without any buffer layer on Si. Figure 2b shows that the AlN buffer layer was introduced between the ZnO film and Si substrate, and the thickness of AlN buffer layer was measured to be 60 nm. It is obvious that the ZnO films in Figure 2b was regularly oriented while it was rambled in Figure 2a. The number of stacking faults and edge dislocations of sample B were obviously less than that of sample A. It can be concluded that with the AlN buffer layer, the crystalline quality of ZnO films was significantly improved.Figure 2

Bottom Line: Meanwhile, the ZnO crystalline quality was significantly improved as verified by both XRD and PL analyses.The valence band offsets have been determined to be 3.06, 2.95, and 0.83 eV for ZnO/Si, ZnO/AlN, and AlN/Si heterojunctions, respectively, and the band alignment of ZnO/Si heterojunction was modified to be 0.72 eV after introducing the AlN buffer layer.Our work offered a potential way to fabricate Si-based ultraviolet light-emitting diodes and improve the device performances.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan, 430072 People's Republic of China.

ABSTRACT
ZnO films were prepared on p-Si (111) substrates by using atomic layer deposition. High-resolution x-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), photoluminescence (PL), and I-V measurements were carried out to characterize structural, electrical, and optical properties. After introducing a 60-nm-thick AlN buffer layer, the growth direction of the ZnO films was changed from [10] to [0002]. Meanwhile, the ZnO crystalline quality was significantly improved as verified by both XRD and PL analyses. It has been demonstrated that the reverse leakage current was greatly reduced with the AlN buffer layer. The valence band offsets have been determined to be 3.06, 2.95, and 0.83 eV for ZnO/Si, ZnO/AlN, and AlN/Si heterojunctions, respectively, and the band alignment of ZnO/Si heterojunction was modified to be 0.72 eV after introducing the AlN buffer layer. Our work offered a potential way to fabricate Si-based ultraviolet light-emitting diodes and improve the device performances.

No MeSH data available.


Related in: MedlinePlus