Fabrication and investigation of extremely thin CdTe absorber layer solar cells

Download

index.pdf

Date

2016

Author

Hosseini, Arezoo

Metadata

Show full item record

Item Usage Stats

241
views

355
downloads

Extremely thin absorber layer (ETA) solar cells aim to combine the advantages of using very thin and cheaply produced absorber layer on nano structured substrates with stability of all-solid-state solar cells. This type of photovoltaic devices use a nano structured interpenetrating heterojunction of thin light-absorbing layer at the interface between an n- and p-type semiconductors. N-type nano structured TiO2 layer is deposited on a Transparent Conducting Oxide coated glass (TCO) substrate, following with the CdTe thin absorber layer deposition to cover the structured wide band gap semiconductor. Finally a void-filling ZnSnTe, optically transparent semiconductor, is deposited onto the absorber layer. This structure is followed by a metallic layer deposition to fulfill the ETA solar cell structure. These types of solar cells with nanostructured n-type material and thin CdTe absorber layer have ahigher absorption rate of light as compared to flat ones. The thickness of the absorber layer is an important parameter for both device operation and the ultimate cost of energy production of these structures. The aim of this thesis study is to investigate the fabrication and performance of different solar cell structures with extremely thin CdTe absorber layer. In this study, a variety of nano structured TiO2 layers were produced by different techniques and characterized as the n-type material for both two- and threecomponent ETA solar cells. The spin coated nano-porous, hydrothermally grown nanowire and electrochemically anodized nanotube TiO2 layers were used as the substrate for sputtered and electrodeposited CdTe layer. It was observed that the sputtered TiO2 layer should be present prior to the nanoporous TiO2 layer formation in order to prevent the shorting between FTO and CdTe layers. Also, ZnTe layer was investigated as the p-type layer for three-component ETA solar cells but due to the high resistance value of this material, ZnTe was substituted with low resistance ZnSnTe layer. Various novel two- and three-component ETA solar cells based on different nano structured TiO2withCdTe and ZnSnTe thin film layer deposited by sputtering and electrodeposition methods, were fabricated in the laboratory scale and characterized. The best efficiency and the device parameters were obtained for the two-component Glass/FTO/NWAsTiO2/Electrodeposited CdTe/Cu-Au structure. Both CdCl2surface treatment and post annealing of the CdTe surface, which were applied prior to the formation of the complete solar cell structure, are found to be essential for the efficiency improvement. The use of nano structured TiO2is also an important factor, which improves the light trapping in this structure. Also the use of electrodeposited CdTe absorber layer, which fills the pores of nano structured TiO2 substrates,improves the efficiency when comparedto the solar cell structure with the sputtered CdTe thin film layer.

Subject Keywords

Solar cells., Absorption., Nanotechnology., Sputtering (Physics)., Nanostructured materials.

URI

http://etd.lib.metu.edu.tr/upload/12619825/index.pdf
https://hdl.handle.net/11511/25509

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Fabrication of thin crystalline silicon solar cells with advanced light trapping Hadibrata, Wisnu; Yerci, Selçuk; Turan, Raşit; Department of Micro and Nanotechnology (2017) Thin crystalline silicon (c-Si) solar cells with thickness in the order of few tens of microns offer many attractive applications, such as, electronic wearables, space probes and satellites thanks to their flexibility and light-weight character. However, reducing the thickness of active layer of silicon solar cells leads to poor light absorption within the silicon layer, especially in the near infrared region of the solar spectrum. The poor absorption becomes problematic for thin c-Si solar cells as it caus...
Production of amorphous silicon / p-type crystalline silicon heterojunction solar cells by sputtering and PECVD methods Eygi, Zeynep Deniz; Turan, Raşit; Erçelebi, Ayşe Çiğdem; Department of Physics (2011) Silicon heterojunction solar cells, a-Si:H/c-Si, are promising technology for future photovoltaic systems. An a-Si:H/c-Si heterojunction solar cell combines the advantages of single crystalline silicon photovoltaic with thin-film technologies. This thesis reports a detailed survey of heterojunction silicon solar cells with p-type wafer fabricated by magnetron sputtering and Plasma Enhanced Chemical Vapor Deposition (PECVD) techniques at low processing temperature. In the first part of this study, magnetron ...
Design of high-efficiency dye-sensitized nanocrystalline solar cells Yavuz, Halil İbrahim; Özenbaş, Ahmet Macit; Erçelebi, Ayşe Çiğdem; Department of Metallurgical and Materials Engineering (2014) Nanocrystalline dye sensitized solar cells (DSSC) technology continues to develop as a better alternative to the silicon based solar cells, which are commercialized. This study aims at finding low cost and highly efficient DSSC design and production methods via examination of effects of both photoanode structure and photon-electron generation mechanism on photoanode layers. This will contribute to the commercialization of DSSC technology. Photoanode structure is examined in four groups; transparent conducti...
Fabrication and characterization of PEDOT:PSS hole transport layers for silicon solar cells Türkay, Deniz; Yerci, Selçuk; Department of Micro and Nanotechnology (2019) Heterojunction silicon solar cells have gained considerable interest in recent years with the demonstration of record-high device performances. However, these devices are typically based on inorganic layers fabricated at high temperatures under vacuum environment, using toxic precursors. The low temperature budget, non-toxic chemical contents, and wide range of adjustability in physical and electrical properties make poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) a promising candidate a...
Structural properties of defected graphene nanoribbons under tension: molecular-dynamics simulations Tüzün, Burcu; Külah, Haluk; Balkan, Raif Tuna; Department of Micro and Nanotechnology (2012) Structural properties of pristine and defected graphene nanoribbons have been investigated by stretching them under 5 percent and 10 percent uniaxial strain until fragmentation. The stretching process has been carried out by performing molecular dynamics simulations (MDS) at 1 K and 300 K to determine the temperature effect on the structure of the graphene nanoribbons. Results of the simulations indicated that temperature, edge shape of graphene nanoribbons and stretching speed have a considerable effect on...

Citation Formats

A. Hosseini, “Fabrication and investigation of extremely thin CdTe absorber layer solar cells,” Ph.D. - Doctoral Program, Middle East Technical University, 2016.