百万像素胶体量子点中波红外焦平面阵列成像技术(特邀)

Megapixel Colloidal Quantum-Dot Mid-Wave Infrared Focal-Plane Array Imaging Technology(Invited)

红外探测及成像具有广泛用途,在红外制导、夜视侦察、安防监控及危化品探测等方面发挥了重要作用。现有红外成像焦平面大多由碲镉汞、二类超晶格、锑化铟等块体半导体材料制成,通过倒装键合的方法实现块体材料与硅基读出电路的信号传输。倒装键合对准困难、操作复杂、对设备依赖性较强,难以满足焦平面阵列规模不断增加和像元尺寸不断减小的制备需求。为解决红外焦平面阵列规模提升的瓶颈,采用碲化汞胶体量子点,通过液相旋涂的方法,突破倒装键合限制,实现硅基读出电路直接片上集成。所制备焦平面阵列规模达1280×1024,像元间距为15μm,80 K工作温度下探测截止波长为4.8μm,响应非均匀性为9%,有效像元率为99.96%,最低噪声等效温差达30 mK,展现了良好的成像性能。

Infrared detection and imaging are crucial in a plethora of applications,such as missile guidance,night vision reconnaissance,security monitoring,and hazardous chemical detection.Current infrared imaging focal planes primarily utilize bulk semiconductor materials such as mercury cadmium telluride,type-II superlattice,and indium antimonide.These materials require flip bonding to electrically couple with silicon-based readout circuits.However,the complexity of this coupling process increases sharply as the array size increases and the pixel size decreases.This study proposes an innovative solution to overcome the flip bonding limitation by using mercury telluride colloidal quantum-dots.By employing a liquid phase spin coating method,we can achieve direct on-chip integration of silicon-based readout circuits.The scale of the resulting focal-plane array reached an impressive 1280×1024,with a pixel spacing of 15 μm.Operating at a temperature of 80 K,the detection cut-off wavelength was found to be 4.8 μm.The response nonuniformity stood at 9%,while the effective pixel rate was measured at 99.96%.Furthermore,the lowest noise equivalent temperature difference reached 30 mK,demonstrating a good imaging performance.