Role of Layer Thickness and Field-Effect Mobility on Photoresponsivity of Indium Selenide (InSe) Based Phototransistors

Abstract Understanding and optimizing the properties of photoactive two-dimensional (2D) Van der Waals solids is crucial for developing optoelectronics applications. The main goal of this work is to present a detailed investigation of layer dependent photoconductive behavior of InSe based field-effect transistors (FETs). InSe based FETs with five different channel thicknesses (t, 20nm < t < 100nm) were investigated with a continuous laser source of λ = 658 nm (1.88 eV) over a wide range of illumination power (P) of 22.8 nW < P < 1.29 μW. All the devices studied showed signatures of photogating; however, our investigations suggest that the photoresponsivities are strongly dependent on the thickness of the conductive channel. A correlation between the field-effect mobility (µFE) values (as a function of channel thickness, t) and photoresponsivity (R) indicates that in general R increases with increasing µFE (decreasing t) and vice versa. Maximum responsivities of ∼ 7.84 A/W and ∼ 0.59 A/W were obtained the devices with t = 20nm and t = 100nm, respectively. These values could substantially increase under the application of a gate voltage. The structure-property correlation-based studies presented here indicate the possibility of tuning the optical properties of InSe based photo-FETs for a variety of applications related to photodetector and/or active layers in solar cells.

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Electronic Transport in Organic Ferroelectric Gate Field-Effect Transistors with ZnO Channel

MRS Proceedings ◽

10.1557/opl.2012.900 ◽

2012 ◽

Vol 1430 ◽

Cited By ~ 1

Author(s):

Hiroaki Yamada ◽

Takeshi Yoshimura ◽

Norifumi Fujimura

Keyword(s):

Hall Effect ◽

Transport Properties ◽

Carrier Concentration ◽

Electronic Transport ◽

Hall Mobility ◽

Field Effect ◽

Field Effect Transistors ◽

Hall Effect Measurement ◽

Field Effect Mobility ◽

Channel Thickness

ABSTRACTThe electronic transport properties of the organic ferroelectric gate field-effect transistors (FeFETs) with the ZnO channel were investigated. The FeFETs with the channel thickness below 100 nm show nonvolatile operation and the on/off ratio of 105. The field-effect mobility decreased with decreasing the channel thickness. From the Hall-effect measurement, it was found that the Hall mobility increases and the carrier concentration decreases after the deposition of the organic ferroelectric gate. From these results, the effect of the ferroelectric polarization on the electronic transport in the FeFETs was discussed.

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Structure - Property Relationships Based on Phenyl-1H-Pyrrole End-Capped Thiophene Semiconductors

Australian Journal of Chemistry ◽

10.1071/ch12112 ◽

2012 ◽

Vol 65 (9) ◽

pp. 1252 ◽

Cited By ~ 5

Author(s):

Ying Liu ◽

Ji Zhang ◽

Yunqi Liu ◽

Gui Yu ◽

Ziyi Ge

Keyword(s):

Field Effect ◽

Heterocyclic Compounds ◽

Field Effect Transistors ◽

Organic Field Effect Transistors ◽

Structure Property ◽

Structure Property Relationships ◽

Active Layers ◽

Structure Property Relationship ◽

Fused Ring ◽

P Type

Thiophene oligomers end-capped with phenyl-1H-pyrrole were used as active layers of organic field-effect transistors. Two types of cores that vary in size and shape of α-linked thiophenes and fused-ring thiophenes were chosen to study the structure–property relationship. The crystal structures, optical, electrochemical and electronic properties were investigated, and the heterocyclic compounds exhibited clear p-type semiconducting behavior.

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Influence of the Electrolyte Salt Concentration on DNA Detection with Graphene Transistors

Biosensors ◽

10.3390/bios11010024 ◽

2021 ◽

Vol 11 (1) ◽

pp. 24

Author(s):

Agnes Purwidyantri ◽

Telma Domingues ◽

Jérôme Borme ◽

Joana Rafaela Guerreiro ◽

Andrey Ipatov ◽

...

Keyword(s):

Phosphate Buffer ◽

Species Interactions ◽

Field Effect ◽

Field Effect Transistors ◽

Limit Of Detection ◽

Debye Length ◽

Intermolecular Forces ◽

Single Layer Graphene ◽

Dna Adsorption

Liquid-gated Graphene Field-Effect Transistors (GFET) are ultrasensitive bio-detection platforms carrying out the graphene’s exceptional intrinsic functionalities. Buffer and dilution factor are prevalent strategies towards the optimum performance of the GFETs. However, beyond the Debye length (λD), the role of the graphene-electrolytes’ ionic species interactions on the DNA behavior at the nanoscale interface is complicated. We studied the characteristics of the GFETs under different ionic strength, pH, and electrolyte type, e.g., phosphate buffer (PB), and phosphate buffer saline (PBS), in an automatic portable built-in system. The electrostatic gating and charge transfer phenomena were inferred from the field-effect measurements of the Dirac point position in single-layer graphene (SLG) transistors transfer curves. Results denote that λD is not the main factor governing the effective nanoscale screening environment. We observed that the longer λD was not the determining characteristic for sensitivity increment and limit of detection (LoD) as demonstrated by different types and ionic strengths of measuring buffers. In the DNA hybridization study, our findings show the role of the additional salts present in PBS, as compared to PB, in increasing graphene electron mobility, electrostatic shielding, intermolecular forces and DNA adsorption kinetics leading to an improved sensitivity.

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