Pulsed-laser deposition of InSe thin films for the detection of thickness-dependent bandgap modification

Layer-structured InSe is one of the intensively studied two-dimensional monochalcogenide semiconductors for optical and electrical devices. Significant features of the InSe device are the thickness dependent bandgap modification resulting in a peak shift of photoluminescence and a drastic variation of electron mobility. In this study, by applying the pulsed-laser deposition technique, we investigated the optical and electrical properties of c-axis oriented InSe films with the thickness varying from a few to hundred nanometers. The energy at the absorption edge systematically shifts from about 3.3 to 1.4 eV with the increasing thickness. The InSe films on Al2O3(0001) are highly resistive, while those on InP(111) are conductive, which probably originates from the valence mismatch effect at the interface. The electron mobility of the conducting charge carrier at the interface of InSe/InP is enhanced in thicker samples than the critical thickness of about 10 nm, corresponding to the bandgap modification characterized by the optical measurement. Therefore, the substrate and the film thickness are critically important factors for the materialization of InSe optical and electrical device applications.Layer-structured InSe is one of the intensively studied two-dimensional monochalcogenide semiconductors for optical and electrical devices. Significant features of the InSe device are the thickness dependent bandgap modification resulting in a peak shift of photoluminescence and a drastic variation of electron mobility. In this study, by applying the pulsed-laser deposition technique, we investigated the optical and electrical properties of c-axis oriented InSe films with the thickness varying from a few to hundred nanometers. The energy at the absorption edge systematically shifts from about 3.3 to 1.4 eV with the increasing thickness. The InSe films on Al2O3(0001) are highly resistive, while those on InP(111) are conductive, which probably originates from the valence mismatch effect at the interface. The electron mobility of the conducting charge carrier at the interface of InSe/InP is enhanced in thicker samples than the critical thickness of about 10 nm, corresponding to the bandgap modification chara...

[1]  Meng Wu,et al.  Origin of n-type conductivity in two-dimensional InSe: In atoms from surface adsorption and van der Waals gap , 2018 .

[2]  Jia Shi,et al.  InSe monolayer: synthesis, structure and ultra-high second-harmonic generation , 2018 .

[3]  Qidai Chen,et al.  Electric field analyses on monolayer semiconductors: the example of InSe. , 2018, Physical chemistry chemical physics : PCCP.

[4]  Yong Xu,et al.  Superconductivity in few-layer stanene , 2017, 1712.03695.

[5]  Xianbin Li,et al.  Native defects and substitutional impurities in two-dimensional monolayer InSe. , 2017, Nanoscale.

[6]  S. Lau,et al.  Wafer-Scale Synthesis of High-Quality Semiconducting Two-Dimensional Layered InSe with Broadband Photoresponse. , 2017, ACS nano.

[7]  K. Novoselov,et al.  High electron mobility, quantum Hall effect and anomalous optical response in atomically thin InSe. , 2016, Nature nanotechnology.

[8]  V. Fal’ko,et al.  Electronic and optical properties of two-dimensional InSe from a DFT-parametrized tight-binding model , 2016, 1611.00262.

[9]  P. Ordejón,et al.  Nanotexturing To Enhance Photoluminescent Response of Atomically Thin Indium Selenide with Highly Tunable Band Gap. , 2016, Nano letters.

[10]  K. T. Law,et al.  Ising pairing in superconducting NbSe2 atomic layers , 2015, Nature Physics.

[11]  Lei Wang,et al.  Multi-terminal transport measurements of MoS2 using a van der Waals heterostructure device platform. , 2015, Nature nanotechnology.

[12]  R. Sankar,et al.  Intrinsic Electron Mobility Exceeding 10³ cm²/(V s) in Multilayer InSe FETs. , 2015, Nano letters.

[13]  W. Cao,et al.  Back Gated Multilayer InSe Transistors with Enhanced Carrier Mobilities via the Suppression of Carrier Scattering from a Dielectric Interface , 2014, Advanced materials.

[14]  Giuseppe Iannaccone,et al.  Electronics based on two-dimensional materials. , 2014, Nature nanotechnology.

[15]  B. Gerardot,et al.  Electronic structure, optical properties, and lattice dynamics in atomically thin indium selenide flakes , 2014, Nano Research.

[16]  R. Sankar,et al.  High performance and bendable few-layered InSe photodetectors with broad spectral response. , 2014, Nano letters.

[17]  Xihong Peng,et al.  Strain-engineered direct-indirect band gap transition and its mechanism in two-dimensional phosphorene , 2014, 1403.3771.

[18]  Likai Li,et al.  Black phosphorus field-effect transistors. , 2014, Nature nanotechnology.

[19]  Walter R. L. Lambrecht,et al.  Quasiparticle band structure calculation of monolayer, bilayer, and bulk MoS 2 , 2012 .

[20]  Q. Xue,et al.  Molecular-beam epitaxy and robust superconductivity of stoichiometric FeSe crystalline films on bilayer graphene , 2011 .

[21]  Luc Henrard,et al.  Charge carriers in few-layer graphene films. , 2006, Physical review letters.

[22]  F. Guinea,et al.  Electronic states and Landau levels in graphene stacks , 2006, cond-mat/0604396.

[23]  Andre K. Geim,et al.  Electric Field Effect in Atomically Thin Carbon Films , 2004, Science.

[24]  K. Ueno,et al.  Investigation of the growth mechanism of an InSe epitaxial layer on a MoS2 substrate , 2000 .

[25]  W. Jaegermann,et al.  Thin film growth and band lineup of In2O3 on the layered semiconductor InSe , 1999 .

[26]  D. Neumark,et al.  ELECTRONIC STRUCTURE OF INDIUM PHOSPHIDE CLUSTERS : ANION PHOTOELECTRON SPECTROSCOPY OF INXPX- AND INX+1PX- (X = 1-13) CLUSTERS , 1999 .

[27]  M. Konagai,et al.  Heteroepitaxy of Layered Compound InSe and InSe/GaSe onto GaAs Substrates , 1998 .

[28]  R. Eppenga.  Electric fields and valence-band offsets in n+n [001] and [110] ZnSe/GaAs, GaAs/Ge, and ZnSe/Ge superlattices , 1989 .

[29]  R. Martin,et al.  Atomic structure and properties of polar Ge-GaAs(100) interfaces , 1981 .

[30]  J. Camassel,et al.  Excitonic absorption edge of indium selenide , 1978 .

[31]  R. Redington,et al.  Electrical and Optical Properties of Indium Selenide , 1954 .