Feb 26, 2014

A facility for plastic deformation of germanium single-crystal wafers

A facility for plastic deformation of single-crystal germanium wafers is described. It consists of a commercial tube furnace which radiates heat to evacuated quartz-glass tubes housing the tools for bending and flattening of the wafers. The facility is semi-automatic and requires minimal attention. All movements and temperature changes are done by a robot via a PLC-control system. Two nine-crystal focusing monochromators (54 × 116 and 70 × 116 mm2) made from 100 wafers with average mosaicity ∼13′ have been constructed. Summaries of the test results are presented.

Source: Physica B: Condensed Matter

If you need more information about A facility for plastic deformation of germanium single-crystal wafers, inexpensive substrates, please visit our website:http://www.germaniumwafers.com, send us email at powerwaymaterial@gmail.com.

Feb 17, 2014

Ambient stability of wet chemically passivated germanium wafer for crystalline solar cells

Surface passivation has been recognized as a crucial step in the evaluation of minority carrier lifetime of photovoltaic materials as well as in the fabrication of high efficient solar cells. Dilute acids of HF and HCl are employed for germanium (Ge) surface passivation. An effective lifetime of passivated Ge wafers has been evaluated by a microwave photoconductive decay (μ-PCD) measurement. Surface recombination velocities,S, of H- and Cl-terminated Ge surfaces are 23 and 37 cm/s, respectively. The stability of passivated Ge surfaces against exposure to air has also been examined. The HCl-passivated Ge surfaces are found to be more robust than HF-passivated surfaces.

Source: Solar Energy Materials and Solar Cells

If you need more information about High mobility single-crystalline-like germanium thin films on flexible, inexpensive substrates, please visit our website:http://www.germaniumwafers.com, send us email at powerwaymaterial@gmail.com.

Feb 7, 2014

High mobility single-crystalline-like germanium thin films on flexible, inexpensive substrates

Single-crystalline-like epitaxial germanium thin films with hall mobility values as high as 833 cm2/Vs have been demonstrated on inexpensive polycrystalline metallic substrates. The dependence of mobility of p-type and n-type germanium films on the deposition temperature has been examined and correlated to microstructural changes. The importance of crystallographic orientation of Ge to achieve these high mobility values has been verified. The mobilities of the epitaxial germanium films on the film thickness for p-type and n-type films with multi-layer architecture with different epitaxial intermediate layers have been investigated. Results show that the increased mobility with increasing germanium film thickness is not just due to crystallographic texture improvement, but could also be a result of decreasing defect density.
Highlights
► Single-crystalline-like films of p-Ge and n-Ge on flexible, inexpensive substrates
► p-Ge and n-Ge films with mobility of 833 and 343 cm2/Vs on these substrates
► Ge grain size, (400) peak intensity, and hall mobility increase rapidly above 630 °C.
► Hole mobility increases and defect density decreases with increasing Ge thickness.

Source:Thin Solid Films

If you need more information about High mobility single-crystalline-like germanium thin films on flexible, inexpensive substrates, please visit our website:http://www.germaniumwafers.com, send us email at powerwaymaterial@gmail.com.