Fig. 1. Band diagram of the transferred electron photocathode

Fig. 2. Schematic of the energy bands of the InP/InGaAsP/InP photocathode^[23]

Fig. 3. Cross-sectional schematic of a p/n junction InP/InGaAsP heterostructure field-assisted photocathode^[7]

Fig. 4. Schematic of the energy bands of the InP/InGaAs photocathode^[6]

Fig. 5. Cross-sectional view of the photocathode of the nanoscale grating antenna^[27]

Fig. 6. InP/In_0.53Ga_0.47As/InP cathode structure^[17]

Fig. 7. Schematic of the TE photocathode structure^[18]

Fig. 8. Schematic of the energy bands of the InGaAs/InAsP/InP photocathode^[5]

Fig. 9. Cross-sectional view of n^-InAs_0.4P_0.6/p^-InAs_0.4P_0.6/p^- In_0.7Ga_0.3As field-assisted photocathode^[8]