Spontaneous Generation of Carrier Electrons at the Interface between Polycrystalline ZnO and Amorphous InGaZnO4. (11th September 2020)

• Record Type: Journal Article
• Authors: Krahl, Fabian; Wu, Yuzhang; Cho, Hai Jun; Karppinen, Maarit; Ohta, Hiromichi
• Is Part Of: Advanced Electronic Materials. Volume 6:Number 10(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-09-11
• Subjects: InGaZnO 4 -- interfaces -- multilayered film -- ZnO; Materials -- Electric properties -- Periodicals; Materials science -- Periodicals; Magnetic materials -- Periodicals; Electronic apparatus and appliances -- Periodicals; 537
• DOI: 10.1002/aelm.202000404
• Languages: English
• ISSNs: 2199-160X

Abstract

Abstract: The interface between two materials can be expected to show exotic optical, electrical, and thermal transport properties due to the difference in chemical bonding and chemical potential. However, in conventional material systems, the volume fraction of the interface is small compared to bulk, and interfacial properties are thus difficult to utilize. In this regard, multilayered films are essential to increase the volume fraction of interfaces and functionalize their properties. Here it is shown that carrier electrons can be generated spontaneously at the interface between polycrystalline ZnO and amorphous (a‐) InGaZnO4 . The electron transport properties are measured of multilayered films composed of c ‐axis oriented polycrystalline ZnO and a‐InGaZnO4 with varying interface density ( d −1 ). Although the carrier concentrations of both ZnO and a‐InGaZnO4 are less than 5 × 10 19 cm −3, the n increases with d −1 and exceedes 10 20 cm −3 . The relatively large interface thermal resistance between ZnO and a‐InGaZnO4 (1.35 m 2 K GW −1 ) indicates the existence of a large difference in the chemical bonding and the chemical potential and thus conduction electrons would accumulate at the interface. Abstract : Spontaneous carrier electron generation at the oxide semiconductor heterointerface is demonstrated using multilayered films composed of ZnO and a‐InGaZnO4 with various interface densities. Relatively large interface thermal resistance (1.35 m 2 K GW −1 ) indicates the existence of large difference in the chemical bonding and that of the chemical potential and thus conduction electrons would be accumulated at the heterointerface.