Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hinge-like structure induced unusual properties of black phosphorus and
  new strategies to improve the thermoelectric performance   We systematically investigated the geometric, electronic and thermoelectric
(TE) properties of bulk black phosphorus (BP) under strain. The hinge-like
structure of BP brings unusual mechanical responses such as anisotropic Young's
modulus and negative Poisson's ratio. A sensitive electronic structure of BP
makes it transform among metal, direct and indirect semiconductors under
strain. The maximal figure of merit $ZT$ of BP is found to be 0.72 at
$800\,\mathrm{K}$ that could be enhanced to 0.87 by exerting an appropriate
strain, revealing BP could be a potential medium-high temperature TE material.
Such strain-induced enhancements of TE performance are often observed to occur
at the boundary of the direct-indirect band gap transition, which can be
attributed to the increase of degeneracy of energy valleys at the transition
point. By comparing the structure of BP with SnSe, a family of potential TE
materials with hinge-like structure are suggested. This study not only exposes
various novel properties of BP under strain, but also proposes effective
strategies to seek for better TE materials.

7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol