An integrated approach to realizing high-performance liquid-junction quantum dot sensitized solar cells

Abstract

Solution-processed semiconductor quantum dot solar cells offer a path towards both reduced fabrication cost and higher efficiency enabled by novel processes such as hot-electron extraction and carrier multiplication. Here we use a new class of low-cost, low-toxicity CuInSexS2−x quantum dots to demonstrate sensitized solar cells with certified efficiencies exceeding 5%. Among other material and device design improvements studied, use of a methanol-based polysulfide electrolyte results in a particularly dramatic enhancement in photocurrent and reduced series resistance. Despite the high vapour pressure of methanol, the solar cells are stable for months under ambient conditions, which is much longer than any previously reported quantum dot sensitized solar cell. This study demonstrates the large potential of CuInSexS2−x quantum dots as active materials for the realization of low-cost, robust and efficient photovoltaics as well as a platform for investigating various advanced concepts derived from the unique physics of the nanoscale size regime.

Células solares sensibilizadas por pontos quânticos

“…51 Em 2013, Klimov e colaboradores construíram uma célula de CuInSeS e depositaram esse PQ sobre o TiO 2 fazendo o uso de ligantes bifuncionais e deixando o substrato imerso na solução de PQ por 36 h. Dessa maneira, eles obtiveram 5,5% de eficiência para tal célula. 105 Já em 2014, Bisquert e colaboradores conseguiram, pela passivação da superfí-cie do CuInS 2 com ZnS, uma eficiência certificada de 6,7%. 106 Tal eficiência é a melhor até o momento para células solares sensibilizadas por pontos quânticos e também demonstra a possibilidade da obtenção de um bom desempenho comparável ou até superior às QDSSC que utilizam metais tóxicos, tais como PQs de cádmio e chumbo.…”

Excited-State Dynamics in Colloidal Semiconductor Nanocrystals

“…Depending on the band alignments, fast electron injection from the NC into the mesoporous film will occur, making it possible to use such superstructures as QDsensitized solar cells, akin to the well-known dye-sensitized Grätzel solar cells [144][145][146][147].…”

Low Cost Pyrite (Fes₂) Nanorod Sensitized Solar Cell​

“…The NR structures open up various possibilities such as band gap tuning by varying the diameter of the NRs along the length [10], orthogonal light absorption and carrier collections directions, minimisation of the recombination of photogenerated carriers by proper channelizing of the carriers [11] in an oriented direction etc. , thus reducing the thickness of the absorber layer in such nano-structured solar cells to several hundred nanometers relatively to the traditional thin film solar cells.…”

“…, thus reducing the thickness of the absorber layer in such nano-structured solar cells to several hundred nanometers relatively to the traditional thin film solar cells. Also the increased semiconductor surface area in NRs improves the semiconductor-electrolyte interface [11,12,13] and thus creates more photocatalytic reactive sites which is supposed to create better hole transport. The NR structures further show enhanced strain relaxation [14,15] opening up to a broader range of absorption energies than is possible with other planar structures.…”

“…In this work we have sensitised FeS 2 nanorods(NRs) of diameter 12 nm on a TiO 2 layer coated over ITO substrate with I / I 3 -and Pt as the electrolyte and the counter electrodes respective. Throughout this work we have adopted the most simple and cost effective methods for the fabrication of solar cells.The NR structures open up various possibilities such as band gap tuning by varying the diameter of the NRs along the length [10], orthogonal light absorption and carrier collections directions, minimisation of the recombination of photogenerated carriers by proper channelizing of the carriers [11] in an oriented direction etc. , thus reducing the thickness of the absorber layer in such nano-structured solar cells to several hundred nanometers relatively to the traditional thin film solar cells.…”