Intrinsic Photoconductivity of Few-layered ZrS2 Phototransistors via Multiterminal Measurements  

作　　者：Rukshan M.Tanthirige Carlos Garcia Saikat Ghosh Frederick Jackson II Jawnaye Nash Daniel Rosenmann Ralu Divan Liliana Stan Anirudha V.Sumant Stephen A.McGill Paresh C.ay Nihar R.Pradhan 

机构地区：[1]Layered Materials and Device Physics Laboratory,Department of Chemistry,Physics and Atmospheric Science,Jackson State University,Jackson,MS 39217,USA [2]National High Magnetic Field Laboratory,Tallahassee,FL 32310,USA [3]Kunming University of Science and Technology,Kunming 650500,China [4]Center for Nanoscale Materials,Argonne National Laboratory,9700 S-Cass Avenue,Lemont,IL-60439,USA

出　　处：《Semiconductor Science and Information Devices》2019年第2期19-28,共10页半导体科学与信息器件（英文）

基　　金：N.R.P.acknowledged NSF-PREM through NSFDMR-1826886,HBCU-UP Excellence in research NSFDMR-1900692;A portion of this work was performed at the National High Magnetic Field Laboratory,which is supported by the National Science Foundation Cooperative Agreement No.DMR-1644779;the State of Florida.This work was performed,in part,at the Center for Nanoscale Materials,a U.S.Department of Energy Office of Science User Facility;supported by the U.S.Department of Energy,Office of Science,under Contract No.DE-AC02-06CH11357.

摘　　要：We report intrinsic photoconductivity studies on one of the least examined layered compounds,ZrS2.Few-atomic layer ZrS2 field-effect transistors were fabricated on the Si/SiO2 substrate and photoconductivity measurements were performed using both two-and four-terminal configurations under the illumination of 532 nm laser source.We measured photocurrent as a function of the incident optical power at several source-drain(bias)voltages.We observe a significantly large photoconductivity when measured in the multiterminal(four-terminal)configuration compared to that in the two-terminal configuration.For an incident optical power of 90 nW,the estimated photosensitivity and the external quantum efficiency(EQE)measured in two-terminal configuration are 0.5 A/W and 120%,respectively,under a bias voltage of 650 mV.Under the same conditions,the four-terminal measurements result in much higher values for both the photoresponsivity(R)and EQE to 6 A/W and 1400%,respectively.This significant improvement in photoresponsivity and EQE in the four-terminal configuration may have been influenced by the reduction of contact resistance at the metal-semiconductor interface,which greatly impacts the carrier mobility of low conducting materials.This suggests that photoconductivity measurements performed through the two-terminal configuration in previous studies on ZrS2 and other 2D materials have severely underestimated the true intrinsic properties of transition metal dichalcogenides and their remarkable potential for optoelectronic applications.

关 键 词：Field-effect transistors Zirconium sulphide PHOTOTRANSISTOR RESPONSIVITY Quantum efficiency 

分 类 号：TN3[电子电信—物理电子学]