Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Influence of molecular beam effusion cell quality on optical and
  electrical properties of quantum dots and quantum wells   Quantum dot heterostructures with excellent low-noise properties became
possible with high purity materials recently. We present a study on molecular
beam epitaxy grown quantum wells and quantum dots with a contaminated aluminum
evaporation cell, which introduced a high amount of impurities, perceivable in
anomalies in optical and electrical measurements. We describe a way of
addressing this problem and find that reconditioning the aluminum cell by
overheating can lead to a full recovery of the anomalies in photoluminescence
and capacitance-voltage measurements, leading to excellent low noise
heterostructures. Furthermore, we propose a method to sense photo-induced trap
charges using capacitance-voltage spectroscopy on self-assembled quantum dots.
Excitation energy-dependent ionization of defect centers leads to shifts in
capacitance-voltage spectra which can be used to determine the charge density
of photo-induced trap charges via 1D band structure simulations. This method
can be performed on frequently used quantum dot diode structures.

31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th