The design strategy and efficiency optimization of a Ge-based n-type metal–oxide–semiconductor field-effect transistor (n-MOSFET) with a Si0.14Ge0.72Sn0.14–Ge0.82Sn0.18–Ge quantum structure used for 2.45 GHz weak energy microwave wireless energy transmission is reported. The quantum structure combined with δ-doping technology is used to reduce the scattering of the device and improve its electron mobility; at the same time, the generation of surface channels is suppressed by the Si0.14Ge0.72Sn0.14 cap layer. By adjusting the threshold voltage of the device to 91 mV, setting the device aspect ratio to 1 μm/0.4 μm and adopting a novel diode connection method, the rectification efficiency of the device is improved. With simulation by Silvaco TCAD software, good performance is displayed in the transfer and output characteristics. For a simple half-wave rectifier circuit with a load of 1 pf and 20 kΩ, the rectification efficiency of the device can reach 7.14% at an input power of –10 dBm, which is 4.2 times that of a Si MOSFET (with a threshold voltage of 80 mV) under the same conditions; this device shows a better rectification effect than a Si MOSFET in the range of –30 dBm to 6.9 dBm.
As an indirect band gap semiconductor, germanium (Ge) can be transformed into a direct band gap semiconductor through some specific modified methods, stress, and alloying effect. Direct band gap-modified Ge semiconductors with a high carrier mobility and radiation recombination efficiency can be applied to optoelectronic devices, which can improve the luminous efficiency dramatically, and they also have the potential application advantages in realizing monolithic optoelectronic integration (MOEI) and become a research hotspot in material fields. Among the various implementations of Ge band gap-type conversion, the related methods that are compatible with the Si process are most promising. It is such a method to etch around the Ge epitaxial layer on the Si substrate and introduce the biaxial tensile stress by SiGe selective filling. However, the influence of the width of the epitaxial layer, Ge composition, and Ge mesa region width on strain distribution and intensity is not clear yet. Accordingly, a finite element stress model of the selective epitaxy-induced direct band gap Ge scheme is established to obtain the material physical and geometric parameters of the Si1−xGex growth region. The result of finite element simulation indicates when the Si1−xGex epitaxial layer is 150–250 nm wide and the Ge composition is 0.3∼0.5, Ge mesa with 20–40 nm in width can be transformed into direct band gap semiconductors in the depth of 0–6 nm. The theoretical results can provide an important theoretical basis for the realization of subsequent related processes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.