### Session A29: Physics and Materials for Inorganic Photovoltaics: I

8:00 AM–10:48 AM, Monday, March 15, 2010
Room: C123

Sponsoring Units: DMP GERA
Chair: Tonio Buonassis, Massachusetts Institute of Technology

Abstract ID: BAPS.2010.MAR.A29.4

### Abstract: A29.00004 : Photovoltaic Properties of TiO2/Cu2O Heterostructure

8:36 AM–8:48 AM

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#### Authors:

Dongdong Li
(Univ of Southern California)

Pai-chun Chang
(Univ of Southern California)

Sheng Chu
(Univ of Southern California)

C.J. Chien
(Univ of Southern California)

Jia G. Lu
(Univ of Southern California)

TiO$_{2}$ is an $n$-type semiconductor with a wide band gap energy of 3.2 eV. It has been known for its photo catalytic effect and widely used in commercial products. Particularly in the growing photovoltaic industry, dye-sensitized solar cells (DSC) made by TiO$_{2}$ nanotube electrode have demonstrated to have conversion efficiency up to 6.9 {\%}. However, the TiO$_{2}$ nanotube based DSC is humbled by the nature of its electrolyte environment. Hence, an all solid-state core shell $p-n$ junction utilizing the TiO$_{2}$ nanostructure solar cell is of great potential to provide another solution for the rising photovoltaic industry. In order to fabricate heterostructures, cuprous oxide (Cu$_{2}$O), a $p$-type semiconductor with a direct band gap of 2.0 eV, is a promising candidate to form $p-n$ heterojunction with TiO$_{2}$. Here we present a method to achieve Cu$_{2}$O/TiO$_{2}$ $p-n$ junction through electrochemical approaches. A self-doping method is addressed on crystallized TiO$_{2}$ nanotubes to further improve the contact and device performance. The photovoltaic property of Cu$_{2}$O/TiO$_{2}$ hetero-structure is measured, giving an open circuit voltage $\sim$0.25 V, a short circuit current $\sim$0.33mA/cm$^{2}$, and filling factor $\sim$27{\%}. Although the efficiency is still low, it demonstrates promising potential to achieve low cost flexible photovoltaic device.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2010.MAR.A29.4