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

Abstract

The vapor transport deposition (VTD) method is regarded as one of the most effective approaches to obtain high-quality Sb2Se3 thin films. However, the orientation and morphology of Sb2Se3 limit the development of Sb2Se3 solar cells. Thus, a method to tailor the surface morphology of Sb2Se3 film growth by VTD is urgently needed. In this work, the growth of the Sb2Se3 thin film and the formation mechanism of Sb2Se3 nanorods appearing on the Sb2Se3 film are carefully studied. Sb2Se3 nanorods with [hk1] orientation and [hk0] orientation are distinguished. By controlling the growth of Sb2Se3 nanorods with [hk1] orientation, the interface defect density is reduced and the quality of the Sb2Se3 thin film is improved. Finally, Sb2Se3 solar cells with the configuration ITO/CdS/Sb2Se3/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 Sb2Se3 device remains after replacing the Spiro-OMeTAD/Au structure with a carbon/Ag structure. This value is the champion efficiency for a VTD-processed Sb2Se3 solar cell with a carbon electrode. This work is expected to offer valuable information for the future development of Sb2Se3 or/and other highly anisotropic materials formed by physical vapor deposition.

Vapor Transport Deposition of Sb2(S,Se)3 Solar Cells with Continuously Tunable Band Gaps

“…The vapor transport deposition (VTD) process could be a preferential choice to fabricate antimony chalcogenide films with various band gaps in view of the gained achievements before. − This process was first developed to produce superstrate CdS/Sb 2 Se 3 solar cells by Wen et al and obtained a certified PCE of 7.6% in 2018 . Subsequently, Zhang et al.…”

Interface Modification Uncovers the Potential Application of SnO2/TiO2 Double Electron Transport Layer in Efficient Cadmium‐Free Sb2Se3 Devices

“…The narrow distribution of sample “W/O” means only Sb 2 Se 3 grain with (221) or (211) orientation is easy to be tunneled under 0.5 V, whereas Sb 2 Se 3 grain with (041), (231), (061), (141), (221), or (211) orientation in sample “With” are all easy to be tunneled under the same voltage. Owing to the anisotropic feature of Sb 2 Se 3 thin films, Sb 2 Se 3 grains can be tunneled over a wider range of resistance when the excitation voltage is increased form 0.5 to 2.0 V. [ 14,34 ] As shown in Figure 4c,d,g,h, a global enhanced c‐AFM current is achieved for both samples. Figure 4k,l uncovers the distribution of c‐AFM current in sample “W/O” is broadened, but an opposite trend is observed in sample “With.” This is attributed to more Sb 2 Se 3 grains with undesirable orientation in sample “W/O” are tunneled.…”

“…Currently, although the champion efficiency of Sb 2 Se 3 TFSC is 9.2%, a pure CdS or Cd doped thin film is prevalently adopted as the electron transport layer (ETL) or buffer layer for most of the efficient Sb 2 Se 3 TFSC with superstrate or substrate configuration. [9][10][14][15][16][17][18][19] Considering the short circuit current density (J sc ) of Sb 2 Se 3 TFSC will be limited by the parasitic absorption of CdS layer (2.4 eV) in wavelength below 520 nm, and the green environmental demands today, avoiding or reducing the usage of cadmium element remains an important issue for the future development of Sb 2 Se 3 technology. Thus, searching for the proper Cd-free ETL is very important.…”

Benign solution-processed (BixSb1−x)2Se3 alloys for short-wavelength infrared mesoporous solar cells

“…40,41 Solution process techniques can have potential advantages over vacuum-based methods because they are low-cost, and require simpler equipment and a lower temperature. For example, deposition of Sb 2 Se 3 using a physical process (e.g., metal evaporation and selenization) involves a temperature of 400-600 1C and a vacuum of the order of 260 À 5 Â 10 À2 mbar, 30,34,[42][43][44][45] while Sb 2 Se 3 synthesis using a solution process requires a temperature in the range of 300-375 1C and ambient pressure. [46][47][48][49][50] Yet, not many solvents can dissolve the precursors at sufficient concentrations.…”

“…For example, deposition of Sb 2 Se 3 using a physical process ( e.g. , metal evaporation and selenization) involves a temperature of 400–600 °C and a vacuum of the order of 260 − 5 × 10 −2 mbar, 30,34,42–45 while Sb 2 Se 3 synthesis using a solution process requires a temperature in the range of 300–375 °C and ambient pressure. 46–50 Yet, not many solvents can dissolve the precursors at sufficient concentrations.…”