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Electron distribution in AlGaN/GaN modulation doped heterostructure

On the contrary, this distribution is decreased within the realistic model of finite potential barrier. Since the key mechanisms limiting the 2DEG mobility in MDHS are alloy disorder and surface roughness scatterings that are very sensitive to the near-interface 2DEG distribution, with a rise of the sheet densities of 2DEG and polarization charges the 2DEG mobility is decreased within the infinite-barrier model, while increased within the finite one. | Communications in Physics, Vol. 22, No. 4 (2012), pp. 327-336 ELECTRON DISTRIBUTION IN AlGaN/GaN MODULATION-DOPED HETEROSTRUCTURES DINH NHU THAO Center for Theoretical and Computational Physics, College of Education, Hue University NGUYEN THANH TIEN College of Science, Can Tho University Abstract. We present a calculation of the distribution of two-dimensional electron gas (2DEG) along the quantization direction in an AlGaN/GaN modulation-doped heterostructure (MDHS). The main confinement sources from ionized donors, 2DEG and polarization charges are properly taken into account. We show that the 2DEG distribution near the MDHS interface depends strongly on the model of potential barrier in use. Within the ideal model of infinite potential barrier, the 2DEG distribution near the interface is increased with a rise of the sheet densities of 2DEG and polarization charges. On the contrary, this distribution is decreased within the realistic model of finite potential barrier. Since the key mechanisms limiting the 2DEG mobility in MDHS are alloy disorder and surface roughness scatterings that are very sensitive to the near-interface 2DEG distribution, with a rise of the sheet densities of 2DEG and polarization charges the 2DEG mobility is decreased within the infinite-barrier model, while increased within the finite one. I. INTRODUCTION Group-III nitride-based heterostructures (HSs) have attracted many intense investigations because of their promising potential for high-voltage, high-power, and hightemperature microwave applications. [1] The mobility of two-dimensional electron gas (2DEG) is a characteristic property of the performance of high electron mobility transistor structures, [2] and it, in AlGaN/GaN HSs, depends strongly on their parameters such as temperature, 2DEG density, and alloy composition. As well known, [1] polarization is an important property of nitride-based HSs. The polar HSs possess a high sheet density of polarization charges bound on the .