Efficient light harvesting in hybrid CdTe nanocrystal/bulk GaAs p-i-n photovoltaic devices

A hybrid colloidal CdTe nanocrystal/bulk GaAs p-i-n heterostructure is demonstrated to have potential for highly efficient light harvesting photovoltaic devices. An array of rectangular channels is fabricated on the surface of the GaAs heterostructure penetrating through its active layer and subsequently filled with water soluble CdTe nanocrystals emitting in the near infrared. Photogenerated carriers in the highly absorbing colloidal nanocrystals are efficiently transferred by means of nonradiative energy transfer to the patterned heterostructure possessing high carrier mobility and converted to electrical current. A threefold enhancement of both photocurrent and monochromatic power conversion efficiency has been achieved.