A very long wavelength infrared（VLWIR） focal plane array based on In As/Ga Sb type-Ⅱ super-lattices is demonstrated on a Ga Sb substrate. A hetero-structure photodiode was grown with a 50% cut-off wavelength of 15...A very long wavelength infrared（VLWIR） focal plane array based on In As/Ga Sb type-Ⅱ super-lattices is demonstrated on a Ga Sb substrate. A hetero-structure photodiode was grown with a 50% cut-off wavelength of 15.2 μm, at 77 K.A 320×256 VLWIR focal plane array with this design was fabricated and characterized. The peak quantum efficiency without an antireflective coating was 25.74% at the reverse bias voltage of-20 mV, yielding a peak specific detectivity of 5.89×10^10cm·Hz^1/2·W^-1. The operability and the uniformity of response were 89% and 83.17%. The noise-equivalent temperature difference at 65 K exhibited a minimum at 21.4 mK, corresponding to an average value of 56.3 mK.展开更多
The microstructures of 7.9/70/30 (Pb92.1La7.9)(Zr70Ti30)O3 (PLZT) transparent ferroelectric ceramics are studied by using the high-resolution electron microscopy (HREM) techniques and electron diffraction. The results...The microstructures of 7.9/70/30 (Pb92.1La7.9)(Zr70Ti30)O3 (PLZT) transparent ferroelectric ceramics are studied by using the high-resolution electron microscopy (HREM) techniques and electron diffraction. The results indicate that the structure of micro-domains presented in the cubic a-phase is exactly the same as that of its ferroelectric β-phase after poling. The fringe-shape micro-regions, appearing in the HREM microphotograph of 7.9/70/30 PLZT, are the result from lattice-overlapping of the orthorhomhic micro-domains and the cubic a-phase matrix. Furthermore, a 2×d111 superlattice along the <111>-direction has been observed in 7.9/70/30 PLZT ceramics. This is probably the result of gliding or rotation on the (111)-plane of self-structure regulation due to point defects.展开更多
基金supported by the National Basic Research Program of China(Grant Nos.2013CB932904 and 2011CB922201)the National Special Funds for the Development of Major Research Equipment and Instruments,China(Grant No.2012YQ140005)the National Natural Science Foundation of China(Grant Nos.61274013,61290303,and 61306013)
文摘A very long wavelength infrared（VLWIR） focal plane array based on In As/Ga Sb type-Ⅱ super-lattices is demonstrated on a Ga Sb substrate. A hetero-structure photodiode was grown with a 50% cut-off wavelength of 15.2 μm, at 77 K.A 320×256 VLWIR focal plane array with this design was fabricated and characterized. The peak quantum efficiency without an antireflective coating was 25.74% at the reverse bias voltage of-20 mV, yielding a peak specific detectivity of 5.89×10^10cm·Hz^1/2·W^-1. The operability and the uniformity of response were 89% and 83.17%. The noise-equivalent temperature difference at 65 K exhibited a minimum at 21.4 mK, corresponding to an average value of 56.3 mK.
文摘The microstructures of 7.9/70/30 (Pb92.1La7.9)(Zr70Ti30)O3 (PLZT) transparent ferroelectric ceramics are studied by using the high-resolution electron microscopy (HREM) techniques and electron diffraction. The results indicate that the structure of micro-domains presented in the cubic a-phase is exactly the same as that of its ferroelectric β-phase after poling. The fringe-shape micro-regions, appearing in the HREM microphotograph of 7.9/70/30 PLZT, are the result from lattice-overlapping of the orthorhomhic micro-domains and the cubic a-phase matrix. Furthermore, a 2×d111 superlattice along the <111>-direction has been observed in 7.9/70/30 PLZT ceramics. This is probably the result of gliding or rotation on the (111)-plane of self-structure regulation due to point defects.
