11:00 〜 11:15
▼ [20a-B12-6] Extensively-Prolonged Electron Lifetime Within Room Temperature Upon InAsGaAs Quantum Dot-in-Well Solar Cell
キーワード：InAs/ GaAs quantum dot-in-well structure, intermediate-band solar cell, long-lived electron
Multitudes of methods have been proposed to date to conquer so-called Schockley-Queisser limit, where the efficiency of single junction solar cell gives in high transmission and thermalization loss. And one of them, intermediate-band solar cell (IBSC), is regarded as the most promising way to jump out from this dilemma. As a complement, the below-bandgap photon absorption upon intermediate energy level provided by additional parallel diode in IBSC gives the chance to boost output current while maintaining high voltage, and thereby, an extremely high efficiency more than 60% under the maximum concentration is theoretically obtained. The fast annihilation process for carriers between intermediate level and ground state, however, plays an unneglectable role in obstructing the functionalization for such devices. In this report, we revealed a remarkably long-lived electron behavior under room temperature upon InAs/ GaAs quantum dot-in-well structure. To visualize the detailed electron decay process, time-resolved photocurrent measurement was applied for theoretical analysis. It is highlighted that the achievement of hundreds of microsecond electron lifetime in proposed structure under room temperature results from highly efficient electron-hole separation process after infrared light irradiation, which also confirms with our previous theoretical calculation. Again, Ti/Au electrode here for top contact also benefits electron performance for better Ohmic contact than others when comparing shorter life in Au-Ge/Au type p-electrode.