Thin-film semiconductors

Patent metadata

Field	Value
Publication number	US-2020373414-A1
Application number	US-202016881500-A
Country	US
Kind code	A1
Filing date	May 22, 2020
Priority date	May 23, 2019
Publication date	Nov 26, 2020
Grant date	—

Abstract

Systems and methods disclosed and contemplated herein relate to manufacturing thin film semiconductors. Resulting thin film semiconductors are particularly suited for applications such as flexible optoelectronics and photovoltaic devices. Broadly, methods and techniques disclosed herein include high-temperature deposition techniques combined with lift-off in aqueous environments. These methods and techniques can be utilized to incorporate thin film semiconductors into substrates that have limited temperature tolerances.

First claim

1 . A method of making a thin film, the method comprising:
depositing a first cadmium layer onto a substrate; depositing a second cadmium layer onto the first cadmium layer, thereby generating a coated substrate; immersing the coated substrate in an aqueous medium; and after immersing the coated substrate, removing a delaminated layer from the substrate, the delaminated layer including the first cadmium layer and the second cadmium layer.

2 . The method according to claim 1 , further comprising applying the delaminated layer to a second substrate.

3 . The method according to claim 2 , the second substrate being selected from a plastic, a fabric, and a cellulose paper.

4 . The method according to claim 1 , wherein a thickness of the first cadmium layer is no greater than 200 nm.

5 . The method according to claim 1 , wherein a thickness of the second cadmium layer is between 0.2 μm to 6 μm.

6 . The method according to claim 1 , wherein depositing the second cadmium layer includes a vapor deposition technique.

7 . The method according to claim 6 , wherein the vapor deposition technique is thermal evaporation.

8 . The method according to claim 1 , wherein a substrate temperature is 20° C. to 25° C. while the first cadmium layer is deposited onto the substrate.

9 . The method according to claim 8 , wherein the substrate temperature is at least 400° C. and no more than 540° C. while the second cadmium layer is deposited onto the substrate.

10 . The method according to claim 1 , wherein the first cadmium layer includes cadmium sulfide (CdS).

11 . The method according to claim 1 , wherein the first cadmium layer includes cadmium selenide (CdSe).

12 . The method according to claim 1 , wherein the second cadmium layer includes cadmium telluride (CdTe).

13 . The method according to claim 1 , wherein an aqueous medium temperature is at ambient temperature before immersing the coated substrate in the aqueous medium.

14 . The method according to claim 1 , wherein the substrate includes silicon material.

15 . A thin film, the thin film being made by a method comprising:
depositing a first cadmium layer onto a substrate; depositing a second cadmium layer onto the first cadmium layer, thereby generating a coated substrate; immersing the coated substrate in an aqueous medium; and after immersing the coated substrate, removing a delaminated layer from the substrate, the delaminated layer including the first cadmium layer and the second cadmium layer.

16 . The thin film according to claim 15 , wherein a thickness of the first cadmium layer is between 100 nm and 250 nm; and
wherein a thickness of the second cadmium layer is between 0.2 μm to 6 μm.

17 . The thin film according to claim 16 , wherein the first cadmium layer includes cadmium sulfide (CdS) or cadmium selenide (CdSe); and
wherein the second cadmium layer includes cadmium telluride (CdTe).

18 . A method of making a thin film, the method comprising:
depositing a first cadmium layer onto a substrate,
wherein a substrate temperature is 20° C. to 25° C. while the first cadmium layer is deposited onto the substrate;
depositing a second cadmium layer onto the first cadmium layer, thereby generating a coated substrate,
wherein the substrate temperature is at least 400° C. and no more than 540° C. while the second cadmium layer is deposited onto the substrate;
immersing the coated substrate in an aqueous medium; and after immersing the coated substrate, removing a delaminated layer from the substrate, the delaminated layer including the first cadmium layer and the second cadmium layer.

19 . The method according to claim 18 , further comprising applying the delaminated layer to a second substrate, the second substrate being selected from a plastic, a fabric, and a cellulose paper,
wherein an aqueous medium temperature is at ambient temperature before immersing the coated substrate in the aqueous medium.

20 . The method according to claim 19 , wherein a thickness of the first cadmium layer is no greater than 250 nm;
wherein a thickness of the second cadmium layer is between 0.2 μm to 6 μm; wherein depositing the second cadmium layer includes a vapor deposition technique; wherein the first cadmium layer includes cadmium sulfide (CdS) or cadmium selenide (CdSe); wherein the second cadmium layer includes cadmium telluride (CdTe); and wherein the substrate includes silicon material.

Assignees

• Univ Utah Res Found

Inventors

• Yoon Heayoung
• Magginetti David

Classifications

• H10P14/2919

  being chalcogenide semiconducting materials not being oxides, e.g. ternary compounds · CPC title

• H10P14/22

  using physical deposition, e.g. vacuum deposition or sputtering · CPC title

• H10P14/38

  characterised by treatments done after the formation of the materials · CPC title

• H10P14/36

  characterised by treatments done before the formation of the materials · CPC title

• H10P14/3466

  Crystal orientation · CPC title