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Fig. 3. Quantum dot area in the modeled device, zoomed in.
Fig. 4. Quantum dot sizes and one-layer QD barriers.
IV. RESULTS AND DISCUSSION
The solar cell was replicated in this work at 300 K solar cell
and an AM1.5 light source based on (SILVACO Software).
The results are compared with a previous study for Boqun
Dong [25]. Where the same structure is used, but the i-region
at the previous study was variable with increasing the number
of quantum dots layers that were inserted into this region.
While in this work the i-region is kept constant with increas-
ing quantum dots layers. In the beginning, a typical p-i-n
GaAs solar cell was simulated, and the outcomes were noted.
The findings for the different added layers (1,5,10,15, and 20)
are then recorded for a p-i-n InAs/GaAs quantum dot solar
cell simulation. To determine the degree of improvement hap-
pened by the addition of quantum dots layers, a significant
solar cell parameters recorded of several parameters, includ-
ing a short circuit current, open circuit voltage, fill factor, and in the i-region, the electrical power will increase to 26.714
conversion efficiency, are measured and compared.
Ahmed, Alsaif & Algwari
Fig. 5. Standard J-V curve with InGaP solar cell and various
InAs QD layer counts.
Table I displays the outcomes of the simulation for six differ-
ent solar cells, where it can be seen that the efficiency, FF, and
Jsc value for all poor. When one layer of InAs QD is inserted
in the i-region, the values of Jsc, FF, and efficiency rise with a
minor increase in Voc. As the number of QD layers increased
to (5, 10, 15, and 20), the Jsc and efficiency rise as well. The
FF rises to 84.213% at QDs with 1-layer and keeps increasing
at 5, 10-layers while at 15, 20-layers, it decreases to 83.93%
and 83.97%.
The J-V curves of both conventional solar cells and quantum
dots solar cells are displayed in Fig. 5 based on the outcomes
of the simulation. The device’s absorption is increased with
the addition of more QDs layers, which accounts for the im-
provement’s significance, especially in current density.
Fig. 6 shows the electrical power of standard p-i-n solar cell
and multi-layers (up to 20-layers) QDs solar cell. It can be
seen that standard solar cell provides an electrical power of
12.52 pW/cm2. When starting to insert the first layer of QDs
pW/cm2. It continuous to increase until it reaches 30.95
pW/cm2 at 20-layers of QDs solar cell.
While Fig. 7 illustrate increasing in power conversion ef-
ficiency (PCE) from (5-20 layers), which values starts at
(27.8457%) for (5- layers) and still increased to be (30.94025%)
for (20-layers).
The spectral response via wavelength are measures using sim-
ulation capabilities as shown in Fig. 8. Fig 8 demonstrates
that the conventional p-i-n solar cell’s spectral response does
indeed converge to zero at wavelengths around 900 nm. Re-
garding the solar cells that contain 1, 5, 10, 15, and 20-layers
of quantum dots. Through Fig. 8, it can be noticed that the re-