Journal
ACS APPLIED MATERIALS & INTERFACES
Volume 10, Issue 50, Pages 43603-43609Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acsami.8b14490
Keywords
Cu(InGa)Se-2 solar cell; CIGS; zinc titanium oxide; buffer/window layer; ALD
Funding
- Swiss Federal Office of Energy (SFOE) [SI/501145-01]
- Swiss National Science Foundation (SNF)-NRP70 [407040_153976, PV2050]
- Swiss State Secretariat for Education, Research, and Innovation (SERI) [15.0158]
- European Union [641004]
Ask authors/readers for more resources
We report on the application of ZnxTiyO deposited by atomic layer deposition (ALD) as buffer layer in thin film Cu(In,Ga)Se-2 (CIGS) solar cells to improve the photovoltaic device performance. State-of-the-art CIGS devices employ a CdS/ZnO layer stack sandwiched between the absorber layer and the front contact. Replacing the sputter deposited ZnO with ALD-ZnxTiyO allowed a reduction of the CdS layer thickness without adversely affecting open circuit voltage (V-OC). This leads to an increased photocurrent density with a device efficiency of up to 20.8% by minimizing the parasitic absorption losses commonly observed for CdS. ALD was chosen as method to deposit homogeneous layers of ZnxTiyO with varying Ti content with a [Ti]/([Ti] + [Zn]) atomic fraction up to similar to 0.35 at a relatively low temperature of 373 K The Ti content influenced the absorption behavior of the ZnxTiyO layer by increasing the optical bandgap >3.5 eV in the investigated range. Temperature-dependent current-voltage (I-V) measurements of solar cells were performed to investigate the photocurrent blocking behavior observed for high Ti content. Possible conduction band discontinuities introduced by ZnxTiyO are discussed based on X-ray photoelectron spectroscopy (XPS) measurements.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available