AVS 58th Annual International Symposium and Exhibition
    Energy Frontiers Focus Topic Thursday Sessions
       Session EN-ThP

Paper EN-ThP7
Carrier Life Time of Several Organic Photovaltanic Cells by using Micro Wave Photoconductive Decay

Thursday, November 3, 2011, 6:00 pm, Room East Exhibit Hall

Session: Energy Frontiers Poster Session
Presenter: Munetoshi Sakai, Kanagawa Academy of Science and Technology (KAST), Japan
Authors: M. Sakai, Kanagawa Academy of Science and Technology (KAST), Japan
K. Naito, KAST, Chuo Univ., Japan
H. Takei, KAST, Japan
K. Nakata, KAST, Tokyo Univ. Sci., Japan
K. Katayama, Chuo University, Japan
K. Takagi, KAST, Japan
A. Fujishima, KAST, Tokyo Univ. Sci., Japan
Correspondent: Click to Email
Recently, the importance of developing the future energy is recognized in various industries. In one of the green innovations, there are great expectations to develop organic photovoltaic cells; Dye sensitized solar cell (DSSC) and Organic thin film solar cell (OTFSC). Organic photovoltaic cells with inexpensive and low resource constraint are currently the subject of great interest and intensive study. DSSC is composed of photo-sensitized anode using molecular dye placed on a porous layer of titanium dioxide nanoparticles, and an electrolyte solution. The photo electrochemical system was known as the Grätzel cell. Electrons at the dye excited because of sunlight move into the titanium dioxide, and are collected by the electrode. On the other hands, OTFSC is composed of organic electronic materials, which have differences in electron affinity and ionization energy, between two metallic conductive electrodes. The layer of the material with higher electron affinity and ionization potential is electron acceptor, and the other layer is electron donor. The hole-electron pairs (excitons) generated in either material, when OTFSC was photoinduced. When most of excitons reach the interface of the electron acceptor and electron donor, excitons break into carriers of holes and electrons efficiently. Electrons and holes move in the acceptor and donor, respectively. The carriers are collected by the electrode in contact with each layer. In either solar cell, the carrier life time would influence the performance of the solar cell, because the carriers (electrons) move through the semiconductor and reach the electrode. Therefore, we investigated the carrier life time of several organic photovoltaic cells by using micro wave photoconductive decay (μPCD). The difference of the carrier life time was discussed from the viewpoints of electrochemistry and quantum mechanics.