Effect of in-Situ Post-annealing on the Second Phase Inclusion Defects
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摘要: 采用传统布里奇曼法生长碲锌镉晶体,在配料过程中添加适当过量的Cd,并在晶体生长结束阶段的降温过程中加入晶锭原位退火工艺,晶体的第二相夹杂缺陷得到了有效抑制。根据晶体第二相夹杂缺陷的形成机理,结合热扩散理论和碲锌镉晶体的P-T相图,研究了退火温度对晶体第二相夹杂缺陷密度和粒度(尺寸)的影响,获得了抑制碲锌镉晶体第二相夹杂缺陷的退火条件。利用优化的退火条件制备碲锌镉晶体,晶体第二相夹杂缺陷的尺寸小于10 μm,密度小于250 cm-2。Abstract: Second-phase-inclusion defects in Bridgman-grown CdZnTe crystals were decreased via post-growth in-situ annealing combined with excess Cd in CdZnTe ingots. Based on the formation mechanism of the second-phase-inclusion defects in Bridgman-grown CdZnTe, the relationship between second-phase-inclusion defects and annealing temperature was studied. The size of second-phase-inclusion defects was reduced to less than 10 μm and their density to less than 250 cm-2 in CdZnTe at an optimized in-situ post-annealing temperature.
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Key words:
- CdZnTe /
- second phase inclusion defects /
- in-situpost-annealing
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图 3 不同组分碲锌镉晶体的P-T相图[8]:1. CdTe;2. Cd0.95Zn0.05Te;3. Cd0.85Zn0.15Te;4. Cd0.5Zn0.5Te;5. Cd0.2Zn0.8Te;6. Cd0.1Zn0.9Te;7. ZnTe;8. Ref[13];9. Ref[13];10. Ref[14]
Figure 3. P-T phase diagram of CdZnTe[8]: 1. CdTe; 2. Cd0.95Zn0.05Te; 3. Cd0.85Zn0.15Te; 4. Cd0.5Zn0.5Te; 5. Cd0.2Zn0.8Te; 6. Cd0.1Zn0.9Te; 7. ZnTe; 8. Ref[13]. 9. Ref[13]; 10. Ref[14]
图 9 两种工艺条件下生长晶体的形貌和EPD情况:(a) 常规(未含退火工艺)生长的碲锌镉晶体形貌;(b) 含退火工艺生长的碲锌镉晶体形貌;(c) 常规(未含退火工艺)生长的晶体典型(图 10中的第6批次)EPD~3×104 cm-2,(d) 含退火工艺生长的碲锌镉晶体典型(图 10中的第6批次)EPD~2.2×104 cm-2
Figure 9. 10 lots of run-to-run X-ray diffraction image and EPD results of CdZnTe with/without in-situ post-annealing, CdZnTe without post-annealing process(a)(c), CdZnTe with post-annealing process(b)(d)
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