Spontaneous Generation of Carrier Electrons at the Interface between Polycrystalline ZnO and Amorphous InGaZnO4

Fabian Krahl, Yuzhang Wu, Hai Jun Cho*, Maarit Karppinen, Hiromichi Ohta

*Corresponding author for this work

Research output: Contribution to journalArticle

1 Citation (Scopus)


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 × 1019 cm−3, the n increases with d−1 and exceedes 1020 cm−3. The relatively large interface thermal resistance between ZnO and a-InGaZnO4 (1.35 m2 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.

Original languageEnglish
Number of pages6
JournalAdvanced Electronic Materials
Publication statusE-pub ahead of print - 11 Sep 2020
MoE publication typeA1 Journal article-refereed


  • InGaZnO
  • interfaces
  • multilayered film
  • ZnO

Fingerprint Dive into the research topics of 'Spontaneous Generation of Carrier Electrons at the Interface between Polycrystalline ZnO and Amorphous InGaZnO<sub>4</sub>'. Together they form a unique fingerprint.

Cite this