Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Enhancing the Open-Circuit Voltage of Perovskite Solar Cells by up to
  120 mV using {\pi}-Extended Phosphoniumfluorene Electrolytes as Hole Blocking
  Layers
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio