Nanoepitaxy Growth of Sb₂Se₃ Nanorod Arrays on Mixed‐Oriented Transparent Conducting Oxide‐Coated Glass for Efficient and Quasiomnidirectional Solar Cells

Abstract

Low‐symmetric and structurally anisotropic materials are of widespread research interest. Antimony selenide and analogues from group V2−VI3 metal chalcogenides, have emerged recently due to their distinctive crystalline symmetries, highly anisotropic electronic and physical properties, Earth abundance, and environmentally friendly characteristics. Its intrinsic quasi‐1D crystal structure leads to much easier and efficient carrier transport along the [hk1] orientation than in other directions. Effective manipulation of the growth orientation and concomitant natural features of the anisotropic materials, which are crucial for the device performance based on the anisotropic Sb2Se3, is still poorly developed. Herein, the growth of monocrystalline Sb2Se3 nanorod arrays (NRAs) along the [hk1] orientation on polycrystalline and mixed‐oriented fluorine‐doped tin oxide (SnO2:F, FTO) glass is carried out under different growth conditions. The thermodynamic and kinetic processes behind the growth of Sb2Se3 NRAs on polycrystalline surfaces are discussed. Solar cells based on the [hk1]‐oriented Sb2Se3 NRAs achieve a power conversion efficiency of 9.0%, comparable with the conversion efficiency of the state‐of‐the‐art Sb2Se3 solar cells. Moreover, these Sb2Se3 NRA solar cells exhibit quasiomnidirectional light absorption characteristics, showing high potential as solar cells with high output power over extended daytime operating hours.

Sb2Se3 Thin‐Film Solar Cells Exceeding 10% Power Conversion Efficiency Enabled by Injection Vapor Deposition Technology

“…For CSS, the contribution of source radiative heating to the surface thermal energy is significant, as the substrate reaches a temperature as high as 250 °C without any substrate heating. [26] The actual temperature of the substrate could reach as high as 370-380 °C during the deposition of high-quality Sb 2 Se 3 absorber layers. In this case, Sb 2 Se 3 nanorods along the c-axis could be obtained in tens of seconds due to its strong anisotropy in bonding property.…”

Crystalline Antimony Selenide Thin Films for Optoelectronics through Photonic Curing

“…The difference between these results demonstrates that the pulse length and radiant energy were crucial in orientation preference. Due to the quasi-one-dimensional crystal structure of Sb 2 Se 3 , films with the ( hkl , l ≠ 0) orientations (i.e., oriented in the (211) and (221) directions) are preferred for PV applications due to better carrier transport and collection through the absorber layer. − Therefore, tuning PC parameters for a 10 ms pulse length can form films with these preferred orientations.…”

“…Antimony selenide (Sb 2 Se 3 ) has emerged as a strong candidate for thin film solar cell applications and water splitting devices with a current power conversion efficiency (PCE) of 10.57% for photovoltaics. − Currently, almost all Sb 2 Se 3 solar cells with high PCE are fabricated by physical vapor deposition at high temperatures (>300 °C) to obtain crystalline Sb 2 Se 3 with (211)- and (221)-oriented thin films (space group Pnma (62)), which are favorable for carrier transport. − Postdeposition annealing techniques are often used to improve the absorber quality (i.e., to increase crystallinity, tune nanoribbon orientation, decrease nonradiative recombination loss, and reduce the bulk trap density), which takes 30 to 120 min. − Because of this, optimization of production throughput by eliminating rate-limiting equilibrium thermal annealing steps is essential to lower the manufacturing cost of device fabrication. In addition, high-temperature annealing causes mechanical failure in flexible substrates due to the mismatch in thermal expansion coefficient between different layers. , Therefore, thermal treatment is undesirable in terms of stability, cost, high volume commercial production, and roll-to-roll manufacturing of such devices.…”

Advances on Sb2Se3 Solar Cells Fabricated by Physical Vapor Deposition Techniques

“…In [39], another CSS growth was adopted to obtain Sb2Se3, and the authors found that the formation of the Sb2Se3 crystal was not strongly dependent on the substrate temperature. However, (hk0) planes, parallel to the substrate, decreased for growth C. Guo et al [45] studied the incorporation of a Ag element into Sb 2 Se 3 obtaining quasi-vertical 1D ribbons at 280 • C, which vanished at 420 • C, where the (120) preferential orientation prevailed.…”

“…In [39], another CSS growth was adopted to obtain Sb 2 Se 3 , and the authors found that the formation of the Sb 2 Se 3 crystal was not strongly dependent on the substrate temperature. However, (hk0) planes, parallel to the substrate, decreased for growth temperature >240 • C (up to 410 • C), while most of the TCs for the (hk1) planes, oblique or perpendicular to the substrate, increased with the growth temperature between 240 • C and 410 • C. Σ TC(hk ) = 0 was 92.2% in this case and AZO/i-ZnO/CdS/Sb 2 Se 3 /FTO/glass solar cells with a 1350 nm (Figure 4b,c) thick Sb 2 Se 3 layer demonstrated a J sc of 29.5 mA/cm 2 and a conversion efficiency of 9.0%.…”