CN-116261375-B - Two-dimensional organic-inorganic heterojunction capable of generating interlayer excitons and preparation method thereof

CN116261375BCN 116261375 BCN116261375 BCN 116261375BCN-116261375-B

Abstract

The invention discloses a two-dimensional organic-inorganic heterojunction capable of generating interlayer excitons and a preparation method thereof, wherein the preparation method comprises the following steps of S1, preparing a double-layer pentacene crystal by a physical vapor transmission method; S2, preparing a single-layer tungsten selenide crystal by a mechanical stripping method or a chemical vapor deposition method, and S3, transferring the single-layer tungsten selenide to double-layer pentacene by dry transfer to prepare the single-layer tungsten selenide/double-layer pentacene heterojunction. The invention prepares the two-dimensional monolayer tungsten selenide/double-layer pentacene heterojunction which can generate interlayer excitons by designing energy band arrangement and adopting a dry transfer process.

Inventors

ZHANG LINGLONG
Yang Shunshun
LIU YOUWEN
TIAN FUGUO

Assignees

南京航空航天大学

Dates

Publication Date: 20260508
Application Date: 20230304

Claims (4)

1. A two-dimensional organic-inorganic heterojunction capable of generating interlayer excitons, characterized in that the heterojunction exhibits two emission peaks in the range 760-950 nm in photoluminescence spectrum measured at 83K low temperature, and the heterojunction is prepared by the steps of: s1, preparing a double-layer pentacene crystal by a physical vapor transmission method; S2, preparing a single-layer tungsten selenide crystal by a mechanical stripping method or a chemical vapor deposition method; And S3, transferring the single-layer tungsten selenide onto double-layer pentacene by using dry transfer to prepare the single-layer tungsten selenide/double-layer pentacene heterojunction.
2. The two-dimensional organic-inorganic heterojunction capable of generating interlayer excitons according to claim 1, wherein the physical vapor transport method in the step S1 comprises the specific steps of tearing a small layer of boron nitride with the thickness of 20nm onto a growth substrate by adopting a mechanical stripping method, placing pentacene crystal powder in the central position of a furnace tube of a tube furnace, placing the growth substrate with boron nitride at the position 13-15cm below the furnace tube, pumping the furnace tube to a vacuum environment of 1X 10 -4 pa, heating the furnace to 130 ℃ to grow pentacene crystals, heating for 30min, naturally cooling a sample to room temperature under the same vacuum, and measuring the number of layers to find the required double-layer pentacene.
3. The two-dimensional organic-inorganic heterojunction capable of generating interlayer excitons as claimed in claim 1, wherein the growth substrate is selected from the group consisting of SiO 2 /Si wafers.
4. The two-dimensional organic-inorganic heterojunction capable of generating interlayer excitons according to claim 1, wherein the dry transfer in step S3 is a PDMS-assisted transfer method.

Description

Two-dimensional organic-inorganic heterojunction capable of generating interlayer excitons and preparation method thereof Technical Field The invention belongs to the field of nano semiconductor devices, and particularly relates to a two-dimensional organic-inorganic heterojunction capable of generating interlayer excitons and a preparation method thereof. Background In the latter molar age, optoelectronic devices that integrate multiple functions of computing, storage, communication, and information processing continue to evolve in directions of faster speed, smaller volume, lower power consumption, cheaper price, and more complete functionality. But conventional silicon-based semiconductors have approached the limit of the material itself. Silicon-based microelectronic technology is challenged by factors such as short channel effect, quantum tunneling effect, power loss, etc., so that two-dimensional semiconductor materials are increasingly being pursued by scientific research and industry as supplements to silicon-based semiconductors. In two-dimensional semiconductor materials, transition metal chalcogenide (TMD) monoatomic layers and other two-dimensional materials can be combined to generate rich exciton physical phenomena, such as dark excitons, interlayer excitons, multi-exciton complexes and the like, and have great development potential in the application fields of exciton condensation, single photon excitation and the like. In addition, organic crystals have advantages such as a huge material library, a clear interface, good compatibility with TMD, high binding energy, high exciton density, and an ultrafast charge transfer process at the organic/inorganic interface, etc. More interestingly, organic crystals exhibit thickness-dependent optical and transport properties on a two-dimensional scale. Thus, two-dimensional organic-inorganic heterojunctions have become ideal platforms for studying new physical phenomena including interlayer excitons/triplet excitons. Currently two-dimensional single layer tungsten selenide (WSe 2)/double layer pentacene (pentacene) heterojunctions have been reported to exhibit type II interlayer triplet excitons formed by intra-layer excitons binding to the charge of different layers. However, no interlayer exciton is found in this heterojunction. Disclosure of Invention It is an object of the present invention to provide a two-dimensional organic-inorganic heterostructure capable of generating interlayer excitons, prepared by the above method. Another object of the present invention is to provide a method of fabricating a two-dimensional organic-inorganic heterojunction capable of generating interlayer excitons. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: in one aspect, the present invention provides a method for preparing a two-dimensional organic-inorganic heterojunction capable of generating interlayer excitons, comprising the steps of: s1, preparing a double-layer pentacene crystal by a physical vapor transmission method; S2, preparing a single-layer tungsten selenide crystal by a mechanical stripping method or a chemical vapor deposition method; s3, transferring the single-layer tungsten selenide onto double-layer pentacene by dry transfer to prepare the single-layer tungsten selenide/double-layer pentacene heterojunction. Preferably, the physical vapor transport method for preparing the double-layer pentacene crystal in the step S1 comprises the specific steps of tearing a small layer of boron nitride with the thickness of 20nm onto a growth substrate by adopting a mechanical stripping method, placing pentacene crystal powder at the center of a furnace tube of a tube furnace, placing the growth substrate with the boron nitride at the position 13-15cm below the furnace tube, heating the furnace to 130 ℃ after the furnace tube is pumped to a vacuum environment of 1X 10 -4 Pa to grow the pentacene crystal, heating for 30min, then naturally cooling a sample to room temperature under the same vacuum, and measuring the layer number to find the required double-layer pentacene. Preferably, the growth substrate is a SiO 2/Si wafer. Preferably, the dry transfer in step S3 is a PDMS-assisted transfer method. In another aspect, the present invention provides a two-dimensional organic-inorganic heterojunction capable of generating interlayer excitons prepared by the above method. Compared with the prior art, the two-dimensional single-layer tungsten selenide/double-layer pentacene heterojunction capable of generating interlayer excitons is prepared by designing energy band arrangement and adopting a dry transfer process. Drawings FIG. 1 is a schematic diagram of a heterojunction of the present invention, wherein the heterojunction comprises a 1-silicon wafer layer, a 2-silicon dioxide layer, 3-few layers of boron nitride, 4-double-layer pentacene, and 5-single-layer tungsten selenide; FIG. 2 is a photograph of a heterojun