Enhanced omnidirectional and weatherability of Cu2ZnSnSe4 solar cells with ZnO functional nanorod arrays

Abstract

This paper presents the use of nanorods of different sizes, deposited from a chemical solution, as an antireflection layer in copper–zinc–tin selenide (CZTSe) solar cells. With the aid of the nanorods, the surface reflection of the CZTSe solar cells was reduced from 7.76% to 2.97%, and a cell efficiency of 14% was obtained as a result. Omni-directional anti-reflection was verified by the angle-dependent reflection measurements. The nanorod arrays also provided the CZTSe solar cells with a hydrophobic surface, allowing it to exhibit high resistance against humidity during weatherability tests. This shows that the surface passivation brought by the nanorod layer at the surface could effectively extend the lifetime of the CZTSe solar cells. The rate of efficiency decay of the CZTSe solar cells was reduced by 46.85% from that of the device without a nanorod array at the surface, indicating that this surface layer not only provided effective resistance against reflection at the device surface, but also served as a passivation layer and humidity-resistant surface-protection layer.

ZnO nanostructured materials for emerging solar cell applications

“…ZnO nanorod arrays are used as an antireection layer in CSZTSe and Si solar cells. 123,124 A decrease in the average reection from 7.76% to 2.97% was detected when switching from bare ZnO to ZnO NRs structure with 900 nm rod length in the CSZTSe solar cell. The trend shows better device performance as the nanorod synthesis time increases up to 9 h (h ¼ 4.08%).…”

“…The trend shows better device performance as the nanorod synthesis time increases up to 9 h (h ¼ 4.08%). 123 It was hypothesized that the ZnO ll the voids and pores better as the synthesis time takes longer, resulting in more intimate interfacial conditions, thus creating a cell with better performance. The SEM image also shows that a longer synthesis time directly translates to longer nanorod length, which, in turn, is accompanied by decreased electrical resistance.…”

Morphological evolution driven semiconducting nanostructures for emerging solar, biological and nanogenerator applications

“…195 ZnO nanostructures have also been used as a part of the antireflection layer in CSZTe and Si solar cells, leading to a reduction in the reflection from 7.76% to 2.97%. 196,197 Further enhancements in the performance of the ZnO nanostructures-based solar cells can be made by increasing the surface area, which can allow for increased rate of kinetics during solar cell functioning, and by enhancing the light absorption capability.…”

Anti-Reflective Coating Materials: A Holistic Review from PV Perspective

“…Extensive research had been carried out in this area, and various Gradient Refractive index (GRIN) nanostructures have been researched to improve the transmittance and to enrich the efficiency of photovoltaic power conversion [18][19][20]. The GRIN configuration is reported in many structures such as nanopillar [21,22], nanowire [23], nanorods [24,25], nano-cone [26,27], nanopyramid [28], and nanotip [29], and these structures are fabricated with a wide range of materials such as silicon, silicon dioxide, metal, metal oxides, polymers and even composites materials. Although these AR coatings exhibit high-performance in broad wavelength and possess omnidirectional antireflective qualities, the fabrication of such structures requires tedious efforts and still faces many problems.…”