Halide perovskites are promising photovoltaic, solar cell, and semiconductor materials. Density-functional theory (DFT) models address compressive and tensile biaxial strain effects on APbCl3, where A = (K, Rb, and Cs). This research shows how A-cation impacts bandgap energy and band structure. The direct bandgap for KPbCl3, RbPbCl3, and CsPbCl3 is found 1.612, 1.756, and 2.046 eV, respectively; increases from A=K to Cs. When spin-orbital coupling (SOC) is introduced, bandgaps in KPbCl3, RbPbCl3, and CsPbCl3 perovskites are reduced to 0.356, 0.512, and 0.773 eV, respectively. More tensile strain widens the bandgap; compressive strain narrows it. Without SOC, the bandgaps of KPbCl3, RbPbCl3, and CsPbCl3 were tuned from 0.486 to 2.213 eV, 0.778 to 2.289 eV, and 1.168 to 2.432 eV, respectively. When the compressive strain is increased, the dielectric constant of APbCl3 decreases (red shift) and increases (blue shift) as the tensile strain is increased. Strain improves APbCl3 perovskite's optical performance.
We demonstrated a nanowire gate-all-around (GAA) negative capacitance (NC) tunnel field-effect transistor (TFET) based on the GaAs/InN heterostructure using TCAD simulation. In the gate stacking, we proposed a tri-layer HfO 2 /TiO 2 /HfO 2 as a high-K dielectric and hafnium zirconium oxide (HZO) as a ferroelectric (FE) layer. The proposed GAA-TFET overcomes the thermionic limitation (60 mV/decade) of conventional MOSFETs' subthreshold swing (SS) thanks to its improved electrostatic control and quantum mechanical tunneling. Simultaneously, the NC state of ferroelectric materials improves TFET performance by exploiting differential amplification of the gate voltage under certain conditions. The most surprising discoveries of this device, which outperforms all previous results, are the very high I ON /I OFF ratio on the order of 10 11 and the enormous on-state current of 135 µA. The incorporation of the NC effect with a 9 nm HZO results in the lowest SS of 20.56 mV/dec (52.38% lower than baseline TFET) and the highest voltage gain of 6.58. Furthermore, the output characteristics revealed a large transconductance (g m ) of 7.87 mS (10 3 order higher than the baseline TFET), drain-induced barrier lowering (DIBL) of 9.7 mV, and a threshold voltage of 0.53 V (37.65% lower than baseline TFET), all of which are significant. Thus, all of the results indicate that the proposed device structure may lead to a new route for electronic devices, creating higher speed and lower power consumption.INDEX TERMS BTBT, gate-all-around structure, heterojunction, nanowire tunnel-FET, negative capacitance.
Two-dimensional hexagonal boron nitride (h-BN) has appeared as a promising material in diverse areas of applications, including as an excellent substrate for graphene devices, deep-ultraviolet emitters, and tunneling barriers, thanks...
For decades, the fundamental driving force behind energy-efficient and cost-effective electronic components has been the downward scaling of electronic devices. However, due to approaching the fundamental limits of silicon-based complementary metal-oxide-semiconductor (CMOS) devices, various emerging materials and device structures are considered alternative aspirants, such as negative-capacitance field-effect transistors (NCFETs), for their promising advantages in terms of scaling, speed, and power consumption. In this article, we present a brief overview of the progress made on NCFETs, including theoretical and experimental approaches, a current understanding of NCFET device physics, possible physical mechanisms for NC, and future functionalization prospects. In addition, in the context of recent findings, critical technological difficulties that must be addressed in the NCFET development are also discussed.
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.