From Flat to Nanostructured Photovoltaics: Balance between Thickness of the Absorber and Charge Screening in Sensitized Solar Cells

详细信息    查看全文

• 作者：Pablo P. Boix ; Yong Hui Lee ; Francisco Fabregat-Santiago ; Sang Hyuk Im ; Ivan Mora-Sero ; Juan Bisquert ; Sang Il Seok
• 刊名：ACS Nano
• 出版年：2012
• 出版时间：January 24, 2012
• 年：2012
• 卷：6
• 期：1
• 页码：873-880
• 全文大小：1059K
• 年卷期：v.6,no.1(January 24, 2012)
• ISSN：1936-086X

文摘

Nanoporous metal oxide electrodes provide a high internal area for dye anchoring in dye-sensitized solar cells, but the thickness required to extinguish the solar photons also enhances recombination at the TiO₂/electrolyte interface. The high extinction coefficient of inorganic semiconductor absorber should allow the reduction of the film thickness, improving the photovoltage. Here we study all-solid semiconductor sensitized solar cells, in the promising TiO₂/Sb₂S₃/P3HT configuration. Flat and nanostructured cells have been prepared and analyzed, developing a cell performance model, based on impedance spectroscopy results, that allows us to determine the impact of the reduction of metal oxide film thickness on the operation of the solar cell. Decreasing the effective surface area toward the limit of flat samples produces a reduction in the recombination rate, increasing the open circuit potential, V_oc, while providing a significant photocurrent. However, charge compensation problems as a consequence of inefficient charge screening in flat cells increase the hole transport resistance, lowering severely the cell fill factor. The use of novel structures balancing recombination and hole transport will enhance solid sensitized cell performance.

Keywords:

dye-sensitized solar cells; photovoltaics; nanostructured cells; TiO₂/Sb₂S₃/P3HT