CdTe Thin Films: Deposition Techniques and Applications

Abstract

The II-IV semiconductor compound, CdTe, has suitable electrical and optical properties as photovoltaic and high-energy radiation sensor material. As an absorber material for thinfilm-based solar cells, CdTe holds the potentiality to fabricate high-efficiency solar cells by means of low-cost technologies. This chapter presents a comprehensive review on the CdTe thin-film deposition techniques as well as on the several configurations for the solar cell structures that have led the best efficiency conversion. Current CdTe thin-film deposition techniques include sputtering, close spaced vapor transport (CSVT), chemical spray pyrolysis, and electrodeposition. These techniques have easily been adapted to deposit polycrystalline CdTe films on various flexible and rigid substrates. In regard to the device structure configuration, a variety of partner materials (transparent contact, optical window, buffer layer) were tested, and CdTe film thickness was varied to develop opaque and semitransparent devices by some techniques mentioned above. In this chapter, we will discuss about each technique used for CdTe thin-film deposition as well as its advantages and disadvantages.

Advancements in Solar Cell Fabrication Techniques: A Comprehensive Review

“…Spu ering is another common method for depositing thin films in thin-film solar cell fabrication. In spu ering, a target material (e.g., cadmium sulfide, indium tin oxide) is bombarded with highenergy ions in a vacuum chamber, causing atoms to be ejected and deposited onto a substrate [11]. Spu ering allows for the deposition of uniform and dense films over large areas, making it suitable for industrial-scale production of thin-film solar cells [12].…”

The effect of oxygen on NiO as a back buffer layer in CdTe solar cells

“…It has been reported that the thermal evaporated Au contact at room temperature has a work function (WF) in the range of 5.1-5.3 eV. [26][27][28] Additionally, CdTe has a WF of 5.7 eV, 29 which creates a high Schottky-barrier height in the range of 0.4-0.6 eV for the hole transport at the CdTe/Au interface. Therefore, the high barrier height impedes hole transport and causes the strong current limiting effect (i.e., roll over) in the light J-V characteristics, which leads to decreased V oc and device efficiency.…”

Comprehensive Review on Thin Film Homojunction Solar Cells: Technologies, Progress and Challenges

“…Two approaches were developed to deposit the absorber layer: (1) the vacuum-based deposition method and (2) the solution-based deposition approach. The vacuum-based deposition approach includes different techniques, such as sputtering, evaporation, and pulsed-laser deposition, while solution-based deposition involves developed techniques with high functionality, such as spin-coating, sol-gel, spray pyrolysis, chemical bath deposition, and screen-printing [28][29][30][31]. It is worth noting that the solution-based deposition approach offers great potential for simple fabrication and lowcost solar cells; however, it suffers from a lower stability compared to those fabricated by vacuum-based deposition approach [32,33].…”