Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Conducting interface in oxide homojunction: understanding of superior
  properties in black TiO2   Black TiO2 nanoparticles with a crystalline-core and amorphous-shell
structure exhibit superior optoelectronic properties in comparison with
pristine TiO2. The fundamental mechanisms underlying these enhancements,
however, remain unclear, largely due to the inherent complexities and
limitations of powder materials. Here, we fabricate TiO2 homojunction films
consisting of an oxygen-deficient amorphous layer on top of a highly
crystalline layer, to simulate the structural/functional configuration of black
TiO2 nanoparticles. Metallic conduction is achieved at the
crystalline-amorphous homointerface via electronic interface reconstruction,
which we show to be the main reason for the superior properties of black TiO2.
This work not only achieves an unprecedented understanding of black TiO2, but
also provides a new perspective for investigating carrier generation and
transport behavior at oxide interfaces, which are of tremendous fundamental and
technological interest.

34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol