- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Degradation of Mg-doped zinc oxide buffer layers in thin film CdTe solar cells
摘要： Cadmium Sulphide is the conventional n-type bu?er layer used in thin ?lm Cadmium Telluride solar cells. It is well known that Cadmium Sulphide causes optical losses and sulphur di?uses into the absorber during high temperature activation. Sputter-deposited Mg-doped ZnO (MZO) has been shown to be an attractive bu?er layer for Cadmium Telluride solar cells due to its transparency and tuneable band gap. It is also stable to high temperature processing and avoids di?usion of elements into the cadmium telluride absorber during the cadmium chloride activation treatment. However, degradation is observed in solar cells incorporating MZO bu?er layers. Analysis of the MZO ?lm surface potential has revealed signi?cant ?uctuations in the thin ?lm work function once the layer is exposed to the atmosphere following deposition. These ?uctuations are attributed to the high reactivity to water vapour of the MgO contained in the MZO ?lms. This has been analysed using X-ray Photoelectron Spectroscopy to determine corresponding changes in the surface chemistry. The Zinc Oxide component is relatively stable, but the analysis shows that MgO forms a Mg(OH)2 layer on the MZO surface which forms a secondary barrier at the MZO/CdTe interface and/or at the interface between MZO and the Fluorine-doped SnO2. This a?ects the Fill Factor and as a consequence it degrades the conversion e?ciency.
关键词： Surface contamination,Degradation,Thin ?lm solar cells,Cadmium telluride,Magnesium-doped zinc oxide,Hydroxide,Bu?er
更新于2025-09-11 14:15:04
-
Dew as a Detrimental Influencing Factor for Soiling of PV Modules
摘要： Soiling of photovoltaic (PV) modules can significantly reduce their energy yield by reflecting or absorbing the incident light and is of great importance for operation and maintenance of PV systems in dusty environments. In this paper, we examine the influence of dew—which is formed on PV modules during night and early morning hours—on soiling processes. Outdoor experiments were performed in desert conditions in Qatar using unheated and heated glass samples supplied with different heating powers, as well as outdoor microscopy studies. In addition, laboratory soiling experiments were performed using different dust types, controlled dust removal by centrifugal forces at different relative humidity levels, and defined dew cycles. Results from both the field tests and laboratory soiling experiments showed a significant impact of dew on particle adhesion, removal, and corresponding soiling rates, which was independent of the dust type. Microstructural investigations using electron microscopy were performed to determine the cause of increased particle adhesion. Heating of glass surfaces during the night can significantly reduce the processes of cementation, particle caking, and capillary aging and, thus, reduce soiling. This study indicates that the prevention of condensation can be a method to mitigate soiling.
关键词： Photovoltaic systems,surface contamination,solar panels,solar energy
更新于2025-09-04 15:30:14