High efficiency solution processed sintered CdTe nanocrystal solar cells: the role of interfaces

Area of Science:

• Materials Science
• Renewable Energy

Background:

• Solution processing of photovoltaic materials enables cost reduction and high throughput.
• Sintering semiconductor nanocrystals into large-grain films is a promising low-temperature fabrication strategy.

Purpose of the Study:

• To fabricate and characterize sintered cadmium telluride (CdTe) nanocrystal solar cells using a solution-based method.
• To investigate methods for enhancing the performance of these novel solar cells.

Main Methods:

• Fabrication of n-ZnO/p-CdTe solar cells via sintering CdTe nanocrystals at 350 °C.
• Performance evaluation including power conversion efficiency (PCE), short-circuit current density (JSC), and open-circuit voltage (VOC).
• Analysis using capacitance measurements and intensity- and temperature-dependent studies.

Main Results:

• Achieved a maximum power conversion efficiency (PCE) of 12.3% for sintered CdTe nanocrystal solar cells.
• Obtained a short-circuit current density (JSC) exceeding 25 mA cm(-2), comparable to traditional methods.
• Demonstrated a significant increase in open-circuit voltage (VOC) through short forward bias application.

Conclusions:

• Low-temperature sintering of CdTe nanocrystals is a viable route for efficient solar cell fabrication.
• The observed VOC enhancement is attributed to the relaxation of an energetic barrier at the ITO/CdTe interface.
• Solution-processed nanocrystal solar cells present a competitive alternative to conventional photovoltaic technologies.