Improving GaInSb crystal quality and optoelectronic properties grown by traveling heater method with rotating magnetic field
摘要
As a III-V group semiconductor material, GaxIn1−xSb(0 < x < 1) crystal is of great application potential in the infrared detection devices and the high electron mobility transistors etc. fields due to its unique advantages, such as the turnabilities of lattice constant, energy bandgap, and cutoff wavelength. Ga0.86In0.14Sb crystals (Φ25 × 100) were prepared with the traveling heater method (THM) applied a rotating magnetic field (RMF), and the influences of the RMF frequency on the structure and properties of GaInSb crystals were investigated. The results show that the crystallization quality of GaInSb crystal improves with the increase of RMF frequency, and the dislocation density decreases from 2.361 × 105 cm−2 to 7.274 × 103 cm−2. And both the radial and the axial segregations of the In component in the crystal decrease. In the range of 20–80 mm of the crystal ingot along the growth axis, the radial segregation of the In component decreases from 0.258 to 0.086 mol%/mm, and the axial segregation does from 0.114 to 0.04 mol%/mm. The electrical properties of the crystal are also improved. The carrier mobility increases from 1.296 × 103 cm2/(V·s) to 1.709 × 103 cm2/(V·s), while the resistivity decreases from 1.822 × 10–3 Ω·cm to 1.377 × 10–3 Ω·cm. In addition, the infrared transmittance of GaInSb crystal increases from 36 to 38%. And the direct bandgap of the crystal decreased from 0.641 eV to 0.630 eV.