Annealing effects on the solution processed CdTe nanocrystals solar cells

• CdTe NCs solar cells with ITO/CdTe/Al structure were prepared by a layer-by-layer solution process.
• The PCE was found strongly related to the annealing (with CdCl2) temperature.
• It was found that promising PCE could be obtained at around 350° annealing temperature.

CdTe nanocrystal (NC) solar cells with Schottky diode configuration of ITO/CdTe/Al structure were prepared by using a layer by layer solution process. The annealing effects on the performance of device was investigated and discussed. It was found that the device performance was strongly related to CdCl2 treatment and annealing temperature. UV–vis, AFM, SEM, EDS etc. were used to characterize the optical and structural properties of CdTe NCs active layer, while the J–V curve of CdTe NCs solar cells was measured using a Keithley 240 source measure unit. It was found that the open circuit voltage (Voc) of devices decreased almost linearly with annealing temperature while short circuit current (Jsc) was kept under a very stable value of about 11 mA/cm2. Device exhibited promising power conversion efficiency (PCE) of 4.09% in the case of 350 °C CdCl2 annealing for 40 s, which was a good efficiency for solution processed CdTe NCs solar cells.

I-V curve of ITO/CdTe NCs/Al device with different annealing temperature.Figure optionsDownload as PowerPoint slide