Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High Performance Direct-Current Generator Based on Dynamic PN Junctions   After the electromagnetic generator, searching for novel electric generators
without strong magnetic field is highly demanded. The generator without strong
magnetic field calls for a physical picture distinct from the traditional
generators. As the counterpart of the static PN junction has been widely used
in the integrated circuits, we develop an electric generator named dynamic PN
generator with a high current density and voltage output, which converts
mechanical energy into electricity by sliding two semiconductors with different
Fermi level. A dynamic N-GaAs/SiO2/P-Si generator with the open-circuit voltage
of 3.1 V and short-circuit density of 1.0 A/m2 have been achieved. The physical
mechanism of the dynamic PN generator is proposed based on the built-in
electric field bounding back diffusing carriers in dynamic PN junctions, which
breaks the equilibrium between drift and diffusion current in the PN junction.
Moreover, the dynamic MoS2/AlN/Si generator with the open-circuit voltage of
5.1 V and short-circuit density of 112 A/m2 (11.2 mA/cm2) have also been
achieved, which can effectively output a direct-current and light up a blue
light-emitting diode directly. This dynamic MoS2/AlN/Si generator can
continuously work for hours without obvious degradation, demonstrating its
unique mechanism and potential applications in many fields where the mechanical
energy is available.

20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex