Influence of the local absorber layer thickness on the performance of ZnO nanorod solar cells

Abstract

The local absorber layer thickness (dlocal) of solar cells with extremely thin absorber was changed between 10 nm and 70 nm. As a model system, ZnO nanorod arrays (electron conductor) with fixed internal surface area coated with In2S3 (absorber) and impregnated with CuSCN (transparent hole conductor) were applied. The performance of the small area solar cells depended critically on dlocal. The highest short circuit current density was reached for the lowest dlocal. In contrast, the highest open circuit voltage was obtained for the highest dlocal. A maximum energy conversion efficiency of 3.4% at AM1.5 was achieved. Limiting factors are discussed.(© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Charge separation and recombination in radial ZnO/In2S3/CuSCN heterojunction structures

“…In particular it was found that the In 2 S 3 thickness plays a crucial role for the cell performance. Although the light absorption could be increased with increasing In 2 S 3 thickness, a drastic drop in the short circuit current was observed for thicker films (9). For very thin films (<10nm) a strong reduction of the open circuit voltage Voc was found.…”

“…For low cost solar cell designs, ZnO nanorod arrays that can be grown at low temperatures by either chemical bath deposition (8) or electrodeposition are particularly promising (7). Recently, we have shown 3.4% conversion efficiency for a nanorod ZnO/In 2 S 3 /CuSCN solar cell (9). In theory, with a surface enhancement by a factor of 10 (roughness factor) efficiencies of about 10%-15% can reasonably be achieved with an absorber thickness of only about 20-30 nm (10).…”

“…This structure is filled with the p-conducting CuSCN by impregnation, before the final metalization is applied. In previous work, the photovoltaic properties of this solar cell as a function of the nanorod length (11), In 2 S 3 absorber thickness (9) and sample annealing (12) were studied. In particular it was found that the In 2 S 3 thickness plays a crucial role for the cell performance.…”

Luminescent Quantum Dots

“…(3) In a typical quantum dot-based solar cell, the quantum dots are attached to a TiO 2 layer with a bifunctional linker molecule, usually mercaptopropionic acid. (3) Several different TiO 2 structures have been utilized in devices, including flat TiO 2 surfaces,(65) spherical nanoparticles,(3) nanowires, (66,67), and nanotubes. (8) Upon absorption of a photon, the photogenerated electron is extracted into the TiO 2 , while the photogenerated hole is extracted into either a hole-conducting polymer or an electrolyte.…”

Plasmonic nano-antenna a-Si:H solar cell

“…This is the category of nanocoax [21], nanocone [22,23], nanodome [24], nanopillar [25,26], nanorod [27][28][29][30][31], and nanowire [32][33][34][35][36][37] solar cells. Employing hydrogenated amorphous silicon (aSi:H) as light absorbing material, an efficiency of up to ~9% [18] has been reported for such nanostructured solar cells.…”