CdTe Schottky diodes from colloidal nanocrystals

Abstract

We have fabricated ultrathin photovoltaic cadmium telluride (CdTe) film solar cells from colloidal nanorod solutions with a power conversion efficiency of 5.0% and internal quantum efficiency approaching unity near the band edge. Sintering of the CdTe nanorod films was necessary to facilitate grain growth and enhanced optical absorption. By analyzing electrode dependence, capacitance-voltage, temperature dependence, and current-voltage characteristics, the device performance is shown to be dominated by the formation of a p-CdTe/Al Schottky junction. The reduced need for material and cheaper processing make this an attractive technology for solar power generation.

Growth of p-CdTe thin films on n-GaN/sapphire

“…The CdCl 2 -treated CdTe/ GaN/Sapphire was more randomly oriented, as compared with as-deposited film. This indicates that CdCl 2 treatment randomly re-orientated the CdTe thin films on GaN/Sapphire substrate, which is consistent with the previous reports [17][18][19][20]. The surface morphology of the CdTe thin film changed significantly after CdCl 2 treatment.…”

Solution‐Processed Heterojunction Solar Cells Based on p‐type PbS Quantum Dots and n‐type Bi2S3 Nanocrystals

“…Since the fi rst report of all-inorganic colloidal quantum dot solar cell based on Cd(Te, Se) QDs with power conversion effi ciency (PCE) of 2.9%, [ 8 ] progress has taken place and CdTe nanorod Schottky junctions have been reported with PCE of 5%. [ 9 ] PbS and PbSe QD solar cells have also been reported in Schottky structures with effi ciencies greater than 2% and sensitivity extending into the infrared well beyond the solar harnessing capabilities of polymers and Cd-based QDs. [10][11][12][13] The inherent limitations of PbS QD Schottky structures in the maximum attainable V oc , limited at Eg/2, and also in EQE, due to the position of the depletion region at the back of the cell, has led to the development of heterojunction PbS QD solar cells with TiO 2 , [ 14 ] ZnO [ 15 ] and PCBM.…”

Solution processed CdTe/CdSe nanocrystal solar cells with more than 5.5% efficiency by using an inverted device structure

“…6) with a tunable band gap have been well exploited, and promising power conversion efficiency (PCE) values of B7% have been reported in the case of PbS-TiO 2 depleted p-n junction solar cells. 16 In order to effectively collect photo-induced carriers in CdTe devices, they have generally been fabricated with the p-n device configuration. Among them, CdTe NC solar cells have attracted much attention since CdTe is a less complex and stable compound, which allows the CdTe devices to be fabricated under ambient conditions.…”