The Very High Efficiency Solar Cell (VHESC) program is developing integrated optical system-PV modules for portable applications that operate at greater than 50% efficiency. We are integrating the optical design with the solar cell design, and have entered previously unoccupied design space. Our approach is driven by proven quantitative models for the solar cell design, the optical design, and the integration of these designs. Optical systems efficiency with an optical efficiency of 93% and solar cell device results under ideal dichroic splitting optics summing to 42Á7 W 2Á5% are described.

We report the demonstration of a two-color infrared focal plane array based on a voltage-tunable quantum dots-in-well ͑DWELL͒ design. The active region consists of multiple layers of InAs quantum dots in an In 0.15 Ga 0.85 As quantum well. Spectral response measurements yielded a peak at 5.5 m for lower biases and at 8-10 m for higher biases. Using calibrated blackbody measurements, the midwavelength and long wavelength specific detectivity ͑D * ͒ were estimated to be 7.1ϫ 10 10 cm Hz 1/2 /W͑V b = 1.0 V͒ and 2.6ϫ 10 10 cm Hz 1/2 /W͑V b = 2.6 V͒ at 78 K, respectively. This material was processed into a 320ϫ 256 array and integrated with an Indigo 9705 readout chip and thermal imaging was achieved at 80 K.

No abstract

Articles you may be interested inTemperature dependent and time-resolved photoluminescence studies of InAs self-assembled quantum dots with InGaAs strain reducing layer structure Some aspects of exciton thermal exchange in InAs quantum dots coupled with InGaAs/GaAs quantum wells J. Appl. Phys. 104, 074315 (2008); 10.1063/1.2965196 Direct imaging of self-organized anisotropic strain engineering for improved one-dimensional ordering of (In,Ga)As quantum dot arrays J. Appl. Phys. 95, 109 (2004); 10.1063/1.1631069Influence of growth conditions on the photoluminescence of self-assembled InAs/GaAs quantum dots

No abstract