Optimization of CdTe solar cell performances using Ga-doped Mg
x
Zn
1-x
O
buffer layers
Samah BOUDOUR
1,2*
, Idris BOUCHAMA
2
, Moufdi HADJAB
1,3
heraga 16014, Algiers / Thin Films and
Applications Unit (UDCMA), Setif-Algeria.
2
Electronic Department, Faculty of Technology, University of Msila, 28000, Msila - Algeria.
3
Applied Materials Laboratory, Research Center, University Djillali Liabes, 22000 Sidi Bel Abbes, Algeria.
*Corresponding authot. Tel: +213(0)661242320; E-mail
In this work
Ga-doped Mg
x
Zn
1−x
O
(GMZO) thin films were developed for application
as high resistance transparent (HRT) buffer layer (BL) in high efficiency CdTe solar cells.
As
the electrical properties of Ga-doped Mg
x
Zn
1−x
O varied between low and high values
according to the gallium and magnesium concentrations, the use of GMZO as both buffer
layers and transparent conducting oxides (TCO) becomes ever more flexible.
We have
performed a computer modeling of
(n+)-GMZO/n-GMZO/p-CdTe/MoTe
2
/Mo new structure
with AMPS-1D software in one dimension under AM 1.5 illumination. The proposed
structure uses n-MoTe
2
layer as a pseudo contact between the CdTe absorber layer and the
Mo back contact. According to some literature data, using high resistive (0.05 at.%) Ga-
doped Mg
0.15
Zn
0.85
buffer layer and high transparency and conductive (0.5 at.%) Ga-doped
Mg
0.10
Zn
0.90
can achieve high efficiency.
The optimal structure was 0.5at.%Ga-doped Mg
0.10
Zn
0.90
/0.05at.%Ga-doped
Mg
0.15
Zn
0.85
/CdTe/MoTe
2
/Mo. The results achieved are: V
CO
= 0.784V, JSC =
28.06mA/cm2, FF = 85.1% and efficiency of 17.019% for thickness of 3500nm and acceptor
concentration of CdTe about of 5
10
16
cm
-1
. We study the effect of 0.5 at.% Ga-doped
Mg
0.05
Zn
0.95
O and 0.5 at.% Ga-doped Mg
0.10
Zn
0.90
O TCO layers on the performance of CdTe
thin film solar cell. The TCO and 0.05 at.%Ga-doped Mg
0.15
Zn
0.85
O buffer layers were
selected, based on the electrical and optical properties data from the papers related to GMZO.
In addition, increasing or decreasing the thickness and the acceptor concentration of CdTe
layers affects photovoltaic values to the worse or to the better.
Key-words:
AMPS-1D, Ga-doped Mg
x
Zn
1−x
O, CdTe, Thin film solar cells.
Corresponding author
:
PS1 6
-162-
