A method for enhancing the performance of pentacene organic field-effect transistor and the structure of pentacence organic field-effect transistor

Patent metadata

Field	Value
Publication number	US-2022013739-A1
Application number	US-202017058652-A
Country	US
Kind code	A1
Filing date	Jul 29, 2020
Priority date	Dec 23, 2019
Publication date	Jan 13, 2022
Grant date	—

Abstract

A method for enhancing the performance of pentacene organic field-effect transistor (OFET): an n-type semiconductor thin film was set as a buffer layer between pentacene and polymer electret in the OFET with the structure of gate-electrode/insulating layer/polymer/pentacene/source (drain) electrode. The thickness of n-type organic buffer layer is 1˜100 nm. The induced electrons at the interface lead to the reduction of the height of the hole-barrier formed at the interface, thus effectively reducing the programming/erasing (P/E) gate voltages of pentacene OFET. The widened distribution region of positive space charges caused by ionized donors in n-type organic buffer layer effectively restricts the back-transfer of holes from polymer to pentacene, thus improving the performance of pentacene OFET, such as the P/E speeds, P/E endurance and retention characteristics.

First claim

1 . A structure configured to enhance performance of pentacene organic field-effect transistor (OFET) memory
the structure of the OFET is the bottom-gate type: the structure from the bottom to the top is gate-electrode/insulating layer/polymer/pentacene/source (drain)-electrode; or the structure of the OFET also can be the top-gate type: the structure from the bottom to the top is source(drain)-electrode/pentacene/polymer/insulating layer/gate-electrode[[. Its characteristics are as followed: an n-type semiconductor thin film is set as a buffer layer between pentacene and polymer electret; the gate electrode is a conductor which resistivity is less than 0.005 Ω·cm, and the insulating layer is an insulator; the polymer is a charge-trapping dielectric, and selected from polystyrene, poly(2-vinyl naphthalene) (PVN) and poly(α-methylstyrene) (PαMS); the thickness of polymer layer is 1-100 nm; N-type semiconductor thin film is a buffer layer, which is an n-type inorganic semiconductor thin film or an n-type organic semiconductor thin film, and its thickness is 1-100 nm; the thickness of pentacene is 1-100 nm; The thickness of source(drain)-electrode is 50-200 nm.

2 . According to the method described in claim 1 , the characteristics are as followed: n-type semiconductor thin film is an n-type organic semiconductor thin film, which includes n-type organic small-molecule semiconductor and n-type polymer semiconductor, such as N,N′-Ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13), N,N′-Bis(3-pentyl) perylene-3,4,9,10-bis (dicarboximide) (EP-PDI) and 1,3,6,8(2H,7H)-Tetraone, 2,7-dicyclohexylbenzo[lmn][3,8]phenanthroline (NDI); It's a crystalline thin film, or a semi-crystalline thin film, or an amorphous thin film.

3 . According to n-type semiconductor thin film described in claim 2 , the characteristics are as followed: the preparation methods of n-type semiconductor thin film include the solution method, spin-coating method, sol-gel method, spray method, silk-screen printing method, ink-jet printing method, thermal evaporation method, and other similar physical and chemical methods; Its thickness is 1-100 nm.

4 . According to the method described in claim 1 , the characteristics are as followed: n-type semiconductor thin film is an n-type inorganic semiconductor thin film including ZnSe, ZnS, ZnO; The preparation methods of n-type inorganic semiconductor thin film includes rf-magnetron sputtering, thermal evaporation and electron-beam evaporation; Its thickness is 1-100 nm; It's a crystalline thin film or a noncrystalline thin film.

5 . According to the method described in claim 1 , the characteristics are as followed: n-type semiconductor thin film can be a hybridized structure with two kinds of n-type semiconductor thin films. It can be an n-type inorganic semiconductor film prepared on the surface of n-type organic small-molecule semiconductor film, or an n-type polymer semiconductor film prepared on the surface of n-type organic small-molecule semiconductor film.

6 . According to the method described in claim 5 , the characteristic is that the thickness of n-type organic small molecule semiconductor film in the hybridized structure is 1-100 nm.

7 . According to the method described in claim 1 , the characteristics are as followed: The electrons with a high density are accumulated at the surface of n-type organic layer near the interface, and the ionized donors (positive charges), which density decreases from the interface to the interior of n-type organic layer, distribute in n-type organic layer. The electrons are induced due to the electrostatic induction of the positively charged interface layer in pentacene.

8 . According to the method described in claim 1 , the characteristics are as followed: In the structure of gate-electrode/insulating layer/polymer/pentacene, the polymer thin film can be polystyrene(PS), poly(α-methylstyrene) (PαMS) or poly(2-vinyl naphthalene) (PVN), etc. The polymer thin film has a charge-trapping ability, and the thickness is 1-100 nm.

9 . According to the method described in claim 8 , the characteristics are as followed: the preparation methods of the polymer thin film include spin-coating method, sol-gel method, spray method, silk-screen printing method, ink-jet printing method, and other similar physical and chemical methods.

10 . Pentacene OFETs obtained using the methods described in claim 1 , the characteristics are as followed: the structure of the OFETs is the bottom-gate type: from the bottom to the top are gate-electrode/insulating layer/polymer/n-type semiconductor buffer layer/pentacene/source(drain)-electrode. The structure of the OFETs also can be the top-gate type: from the bottom to the top are source(drain)-electrode/pentacene/n-type semiconductor buffer layer/polymer/insulating layer/gate-electrode.

11 . A structure configured to enhance performance of pentacene organic field-effect transistor (OFET) with n-type semiconductor interlayer,
said structure of the OFET is a bottom-gate type: the structure from the bottom to the top is gate-electrode/insulating layer/polymer/pentacene/source (drain)-electrode; or said structure of the OFET is a top-gate type: the structure from the bottom to the top is source(drain)-electrode/pentacene/polymer/insulating layer/gate-electrode;
said structure of the OFET is characterized by:
an n-type semiconductor thin film is set between the insulating layer and the polymer electret;
the gate electrode is a conductor having a resistivity less than 0.005 Ω·cm, and the insulating layer is an insulator;
N-type semiconductor thin film is an n-type inorganic semiconductor thin film or an n-type organic semiconductor thin film;
the polymer is a charge-trapping dielectric, a thickness of the polymer layer is 1-100 nm;
the thickness of the pentacene is 1-100 nm;
the thickness of source(drain)-electrode is 50-200 nm.

12 . According to the method described in claim 11 , the characteristics are as followed: n-type semiconductor thin film is an n-type inorganic semiconductor thin film including ZnSe, ZnS, ZnO, amorphous indium-gallium-zinc oxide (IGZO), an oxygen-deficient oxide film and an oxygen-deficient composite oxide film, such as TiO 2-x and ZrHfO 2-x ; The preparation methods of n-type inorganic semiconductor thin film includes rf-magnetron sputtering, thermal evaporation and electron-beam evaporation; Its thickness is 1-200 nm; It's a crystalline thin film or a noncrystalline thin film.

13 . According to the method described in claim 11 , the characteristics are as followed: n-type semiconductor thin film is an n-type organic semiconductor thin film, which includes n-type organic small-molecule semiconductor and n-type polymer semiconductor, such as N,N′-Ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13), N,N′-Bis(3-pentyl) perylene-3,4,9,10-bis (dicarboximide) (EP-PDI) and 1,3,6,8(2H,7H)-Tetraone, 2,7-dicyclohexylbenzo[lmn][3,8]phenanthroline (NDI), but not limited to the above mentioned organic films; It's a crystalline thin film, or a semi-crystalline thin film, or an amorphous thin film.

14 . According to n-type semiconductor thin film described in claim 13 , the characteristics are as followed: the preparation methods of n-type organic semiconductor thin film include the solution method, spin-coating method, sol-gel method, spray method, silk-screen printing method, ink-jet printing method, thermal evaporation method, and other similar physical and chemical methods; Its thickness is 1-100 nm.

15 . According to the method described in claim 11 , the characteristics are as followed: n-typ

Assignees

• Nanjing University Of Technology

Inventors

• Kang Limin
• Wang Yiru
• Yin Jiang
• Xia Yidong
• Liu Zhiguo

Classifications

• H01L51/052 Primary

  Electricity · mapped topic

• H10K85/141 Primary

  comprising aliphatic or olefinic chains, e.g. poly N-vinylcarbazol, PVC or PTFE · CPC title

• H10K10/46 Primary

  Field-effect transistors, e.g. organic thin-film transistors [OTFT] (H10K10/43 takes precedence) · CPC title

• H10K10/471 Primary

  the gate dielectric comprising only organic materials · CPC title

• H10K85/111

  comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene · CPC title