Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unveiling the dopant segregation effect at hematite interfaces   Understanding the effects of atomic structure modification in hematite
photoanodes is essential for the rational design of high-efficiency
functionalizations. Recently it was found that interface modification with
Sn/Sb segregates considerably increases hematite photocatalytic efficiency.
However, the understanding of the different electronic effects of these
modifications at the atomic level is still lacking. This letter describes the
segregation effects of two different dopants-Sn and Sb-on both the solid-solid
(grain-boundaries) and solid-liquid interfaces (surfaces) of hematite. Within
an ab-initio approach, we quantitatively extract the potential barrier
reduction on polycrystalline interfaces due to the dopant, which causes an
increase in the inter-grain electron transport. Concomitantly, the dopants'
segregation on hematite surfaces results in a decrease of the oxygen vacancy
formation energy. Such vacancies lead to the experimentally observed rise of
the flat-band potential. The comprehension of the electronic effects of dopants
on both types of interfaces explains the experimental peak efficiency of
interface-modified hematite with dopant segregates, also enabling the control
and design of interfaces for different higher-efficiency applications.

2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio