Fig. 1. The energy band alignments for the ICIP，the arrow shows the transport direction of the electron，and the green lines shows the energy level for the electron or holes in the superlattices and quantum wells

Fig. 2. （a）The relationship between the detectivity and absorber thickness for single-absorber detector，（b）the maximum detectivity of current-matched structure for different number of stage and diffusion length

Fig. 3. Responsivity spectrum for the（a）one-stage ICIP and（b）two-stage ICIP at different temperatures^［23］

Fig. 4. （a）The relationship between the responsivity for the three-stage，five-stage and ten-stage ICIPs at the bias of -200 mV and the wavelength of 4.1 μm，（b）detectivity of ten-stage ICIP with immersion lens at the operating temperature of 300 K

Fig. 5. Infrared images of mid-wavelength ICIP FPA working at（a）125 K，（b）135 K，（c）145 K

Fig. 6. （a）Room temperature frequency response of the five-stage ICIP versus bias with 20 µm device diameter，（b）frequency response versus device diameter under the bias of -5 V ^［25］

Fig. 7. （a）Detectivity of ten-stage ICIP at the operating temperature of 220 K，（b）the response time under the bias of -1.3 V，the inset shows the ten-stage ICIP with TEC package

Fig. 8. The schematic illustration of the ICLED

Fig. 9. （a）Electroluminescence spectra for the two-stage ICLED，（b）electroluminescence spectra for the five-stage ICLED，（c）output power for the five-stage ICLED，（d）wall plug efficiency for the five-stage ICLED with a mesa size of 400×400 μm^2［26］