First-principles based ballistic transport simulation of monolayer and few-layer InSe FETs

Abstract

Ballistic performance of monolayer and few-layer indium selenide (InSe) based field effect transistors (FETs) is evaluated based on first principles calculation using density functional theory (DFT) and top-of-the-barrier transport model. Quantum confinement in atomically layered InSe is taken into account by self-consistently solving the Poisson and Schrödinger equations based on effective mass approximation. DFT calculations suggest that the electronic band structure of layered InSe strongly depend on the layer number, where the bandgap energy as well as electron effective mass gradually increases with layer number decreasing. Ballistic transport property as a function of layer number in InSe FET is calculated based on the thickness-dependent effective mass, and analyzed by the inversion density, injection velocity and quantum capacitance separately. Simulation results reveal that the InSe FETs with reduced layer number provide better electronic performance, showing great potential for future high-performance complementary metal-oxide-semiconductor application.

Phonon and electron transport in Janus monolayers based on InSe

“…The previous result of Ref. 34 SSe is comparable to that of monolayer InSe, due to the competition effect between phonon group velocity and lifetime. Moreover, the electron mobility of monolayer In 2 SeTe is higher than that of monolayer InSe, due to that smaller electron effective mass and deformation potential, respectively.…”

“…The electron effective mass m * (1/m0) along x and y axis, 2D elastic module C2D (J/m 2 ), deformation potential constant E1 (eV) and room-temperature µ (cm 2 /V/s) of monolayer InSe and its Janus derivatives along the x axis. The previous result of Ref 34. is listed for a comparison.…”

Liquid‐Exfoliated Few‐Layer InSe Nanosheets for Broadband Nonlinear All‐Optical Applications

“…The bulk InSe is a direct bandgap, and the bandgap value is suitably 1.25 eV, which is suitable for making a light‐emitting device. [ 26 ] In addition, experiments and theories have proved that due to the quantum confinement effect, as the number of InSe layers is reduced to few layers, it will undergo a transition from the direct bandgap to the indirect bandgap, and the bandgap value increases to 2.6 eV, [ 27–29 ] which makes it have a broad prospect in the application of optoelectronics. Hybridization of the In and Se atomic orbitals results in a relatively light electron effective electron mass (0.143 m 0 ) [ 30 ] in the plane of the layer, which results in a field effect transistor fabricated using multiple layers of InSe with high electron mobility rate (10 3 cm 2 V −1 s −1) ) [ 20 ] and on/off current ratio (10 8 ) [ 31 ] over the transition metal disulfide at room temperature.…”

Remote Phonon Scattering in Two-Dimensional InSe FETs with High-κ Gate Stack

“…We start the calculation by obtaining the electrostatic characteristic of the two-dimensional electron gas (2DEG) in InSe layer by self-consistently solving the Poisson and Schrödinger equations using the effective mass approximation with nonparabolicity correction, inherently accounting for the quantum confinement effects [19]. Particularly the energy dispersion of 2D-layered InSe is described by the thickness-dependent effective masses obtained from first-principles calculation, as shown in our previous work [14]. Next, the matrix elements and the scattering rates are calculated through the Fermi golden rule [19].…”

“…However, the charge transport properties in InSe FET have not been well understood and starve for comprehensive investigation. More recently, the ballistic performance of mono- and multi-layer InSe FET is studied by the first-principles calculation and the top of the barrier model [14], and temperature-dependent phonon-limited mobility is estimated by the physical modeling of intrinsic scattering mechanisms [15]. On the other hand, charge transport behavior is very sensitive to external surroundings, such as gaseous adsorbates from air and trapped charges in substrates [16], and their electronic performance is generally lower than their intrinsic values.…”