Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-performance planar light-emitting diode   Planar light-emitting diodes (LEDs) fabricated within a single high-mobility
quantum well are demonstrated. Our approach leads to a dramatic reduction of
radiative lifetime and junction area with respect to conventional vertical
LEDs, promising very high-frequency device operation. Devices were fabricated
by UV lithography and wet chemical etching starting from p-type
modulation-doped AlGaAs/GaAs heterostructures grown by molecular beam epitaxy.
Electrical and optical measurements from room temperature down to 1.8 K show
high spectral purity and high external efficiency. Time-resolved measurements
yielded extremely short recombination times of the order of 50 ps,
demonstrating the relevance of the present scheme for high-frequency device
applications in the GHz range.

23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs