Influence of furnace temperature gradient on the crystal structure and photoelectric properties of GaInSb crystals grown with traveling heating method
摘要
Ga0.92In0.08Sb crystals (25 mm in diameter, 120 mm in length) were grown with both the Vertical bridgman method (VB) and the Traveling Heater Method (THM). Compared with the VB, the THM notably reduced In segregation and dislocation density in the ingot significantly, thereby enhancing the crystal’s electrical and optical properties. The influences of the furnace temperature gradient during the THM growth on the crystal structure and the electrical and optical properties were investigated. The crystallization quality improved with the furnace temperature gradient increase from 10 to 15 °C cm: the axial segregation of In decreased from 0.108 mol%/mm to 0.068 mol%/mm, while the radial segregation increased from 0.069 mol%/mm to 0.091 mol%/mm, and the dislocation density also decreased from 2.917 × 103 cm⁻2 to 1.982 × 103 cm⁻2. Correspondingly, the carrier mobility increased from 1.598 × 103 cm2/(V⋅s) to 1.885 × 103 cm2/(V⋅s), the resistivity decreased from 1.411 × 10⁻3 Ω⋅cm to 1.262 × 10⁻3 Ω⋅cm, and the infrared transmittance increased from 45 to 50%. These results confirmed THM as a superior method to grow high-quality GaInSb crystals, and the temperature gradient optimization enabled further property improvement.