[21p-B202-1~13] 13.9 Compound solar cells

▼ [21p-B202-13] Electrical Properties of AlGaAs/GaAs-Based Two-Step Photon Up-Conversion Solar Cells with Doubled heterointerfaces

〇Hambalee Mahamu¹, Shigeo Asahi¹, Takashi Kita¹ (1.Kobe Univ.)

Keywords:Solar Cells, Quantum Dots, Photon Up-coversion

We fabricated two-step photon up-conversion solar cells based on the utilization of Al_0.7Ga_0.3As, Al_0.3Ga_0.7As and GaAs with the incorporation of InAs quantum dots at the heterointerface created between these semiconductors. These solar cells are called doubled-heterointerface two-step photon up-conversion solar cells (DTPU-SCs). The characteristics of intensity-dependent photocurrent measured from DTPU-SCs were achieved. We activated DTPU-SCs by the irradiation of 784-nm photons in order to selectively excite GaAs. The photocurrent was clearly detected suggesting the thermal activation process occurred at the doubled-heterointerface. Moreover, additional infrared photons were applied in order to ensure the absorption of below-bandgap photons. We observed an obvious enhancement of the photocurrent pointing to the absorption of the infrared photons at the heterointerfaces. Therefore, a tripled photoexcitation may happen, and hence, the improvement of below-bandgap absorptivity.