P-Type InGaAsP Coolers for Integrated Optic Devices
CALIFORNIA UNIV SANTA BARBARA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
Pagination or Media Count:
Single stage heterostructure coolers based on thermoelectric and thermionic cooling in p- type InGaAsP superlattice structures have been fabricated and characterized. The effect of ambient temperature and the device size have been studied. Experimental results showed 0.5 degree centigrade cooling below the ambient temperature at 25C. This cooling over 1 mm thick superlattice barrier corresponds to cooling power densities on the order of 200 Wcm2. The device cools by a factor of two better at higher temperatures 70C. This is due to the reduction of the superlattice thermal conductivity and the broadening of the electronic distribution function at higher temperatures. 150x150 um2 devices provide largest cooling at room temperature while the optimum device size shrinks as the temperature increases. Simulations results that take into account finite thermal resistance of the InP substrate, the effect of the contact resistance, heat generation in the wire-bonds and metallic pads on top of the device predict accurately the optimum cooling of these micro refrigerators. By eliminating the major parasitic sources of heating reducing the contact resistance to 5x10-7 ohm-cm2, and optimizing the metallic contacts on top of the devices, simulations show that one can achieve up to 15oC cooling 10 s of kWcm2 cooling power with single stage p-InGaAsP thin film coolers.
- Inorganic Chemistry
- Electrical and Electronic Equipment