Remarkable Sb2Se3 Solar Cell with a Carbon Electrode by Tailoring Film Growth during the VTD Process

The vapor transport deposition (VTD) method is regarded as one of the most effective approaches to obtain high-quality Sb 2 Se 3 thin films. However, the orientation and morphology of Sb 2 Se 3 limit the development of Sb 2 Se 3 solar cells. Thus, a method to tailor the surface morphology of Sb 2 Se 3 film growth by VTD is urgently needed. In this work, the growth of the Sb 2 Se 3 thin film and the formation mechanism of Sb 2 Se 3 nanorods appearing on the Sb 2 Se 3 film are carefully studied. Sb 2 Se 3 nanorods with [hk1] orientation and [hk0] orientation are distinguished. By controlling the growth of Sb 2 Se 3 nanorods with [hk1] orientation, the interface defect density is reduced and the quality of the Sb 2 Se 3 thin film is improved. Finally, Sb 2 Se 3 solar cells with the configuration ITO/CdS/Sb 2 Se 3 /C/Ag achieve an efficiency of 6.09% with an open circuit voltage ( V oc ) deficit decreased by 34 mV, wherein over 85% of the efficiency of the Sb 2 Se 3 device remains after replacing the Spiro-OMeTAD/Au structure with a carbon/Ag structure. This value is the champion efficiency for a VTD-processed Sb 2 Se 3 solar cell with a carbon electrode. This work is expected to offer valuable information for the future development of Sb 2 Se 3 or/and other highly anisotropic materials formed by physical vapor deposition.