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This paper describes an innovative design for a nominal 20 kW, integrated, high-concentration (260X) photovoltaic (IHCPV) system which has been developed for costeffective, utility-scale bulk power generation. This technology recently set a new world record for efficiency : 20.3% under STC (18.5%, >20 kW at PVUSA operating conditions). High-concentration PV systems offer several advantages for low cost power generation: (1) cost reduction through the optimum utilization of silicon, (2) higher conversion cell (hence system) efficiency at concentration vs. one-sun, and (3) inherently higher capacity factor in high direct normal insolation areas because of its built-in tracking. Previously little progress has been made in deploying HCPV for large-scale electricity generation because of: (1) the lack of a stable, high performance, high-concentration solar cell, and (2) the high cost associated with the PV modules, structure, tracking system, and ancillary equipment. With the arrival of a stable high performance cell developed by AMONIX, high-concentration PV systems can now be realized. A novel integrated system concept greatly reduces the costs associated with system hardware and labor by; (1) integrating the load bearing structure and the Fresnel lenslreceiver plate elements eliminating the need for separate modules, and (2) use of a manufacturing-worthy receiver plate which makes use of "circuit-board" construction techniques. A full-scale 20 kilowatt IHCPV system has been deployed, and test results which validate the system design are reported. The IHCPV system development is complete and only volume production, not technical breakthroughs, is needed to meet the cost goals of <$2.00/watt at multi-megawatt levels.

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Characteristics of an InGaP / Al X Ga 1 − X As / GaAs composite-emitter heterojunction bipolar transistor (CEHBT)A GaAsNSb heterojunction bipolar transistor ͑HBT͒ structure was grown by solid source molecular beam epitaxy. The fabricated HBT showed a reduction in the turn-on voltage of ϳ195 mV when GaAs 0.915 N 0.005 Sb 0.08 was used as the base material. The small knee voltage ͑Ͻ1 V͒ of the GaAsNSb HBT indicates that the current blocking effect is small. Significant gain degradation in the GaAsNSb HBT was observed when the nitrogen ͑N͒ composition was increased to 2%. The results show that the dilute nitride GaAsNSb materials have potential for reducing the turn-on voltage in GaAs HBTs.

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