Fig. 1. PM-OPDs with the characteristic of single charge carrier transport. (a) Schematic diagram of working mechanism^[23]; (b) hole mobility and EQE spectra of PM-OPDs with different self-assembly time^[36]; (c) working mechanism, responsivity, and detectivity D^* of PM-OPDs with BDP-OMe∶C₆₀ as the active layer^[37]

Fig. 2. Analysis of PM-OPDs working mechanism. (a) EQE spectra of PM-OPDs under reverse bias^[35]; (b) distribution of trapped electrons in the active layer^[35]; (c) EQE spectra under forward bias^[35]; (d) normalized transient photocurrent curves generated by incident light of different wavelengths under both positive and negative biases^[35]; (e) variation of EQE spectrum with the distribution of trapped electrons near the interface^[40]

Fig. 3. EQE spectra of broad response PM-OPDs based on different active layers. (a) P3HT∶PCBM and P3HT∶DC-IDT2T^[46]; (b) P3HT∶PY3Se-1V^[48]; (c) PBDB-T∶Y6^[49]; (d)‒(f) absorption spectra, EQE spectra, and response speed of the components broad response PM-OPDs of the active layer in TPD-3∶Y6-Se-HD^[37]

Fig. 4. Performance and application exploration of broad response PM-OPDs based on different active layers. (a) PMBBDT∶Y6^[51]; (b) blood oxygen saturation detection system and measuring results^[51]; (c) optical pulse counting system using PBDB-T∶PYF-T-o as active layer^[52]

Fig. 5. Broad response PM-OPDs based on P3HT∶PTB7-Th∶PC₇₁BM. (a)‒(c) Energy level diagram, absorption spectra, responsivity, and D^* spectra of the active layer P3HT∶PTB7-Th∶PC₇₁BM in broad response PM-OPDs^[57]; (d) absorption spectra of three components in active layers and EQE spectra of broad response PM-OPDs based on the active layer P3HT∶PMBBDT∶PTz-PT with or without the third component^[31]; (e) EQE spectra of PM-OPDs based on the active layer P3HT∶PTB7-Th∶IEICO with or without the third component^[58]

Fig. 6. Schematic working mechanism and EQE spectra of broad response PM-OPDs based on double-layer scheme. (a) PM6∶Y6 as photon harvesting layer and P3HT∶PC₇₁BM as photomultiplication layer^[59]; (b) SubPc∶C₆₀ as photon harvesting layer and C₆₀∶MoO₃ as photomultiplication layer^[60]; (c) PBDB-T∶Y6 as photon harvesting layer and CdSe as photomultiplication layer^[61]

Fig. 7. Narrow response PM-OPDs with TAPC∶C₆₀ as active layer^[70]. (a) Absorption spectra of each component in the active layer; (b) EQE spectra under different reverse biases; (c) schematic of flexible ultraviolet light monitor

Fig. 8. Narrow response PM-OPDs based on CIN concept. (a) Trapped electron distribution in the active layer of P3HT∶PC₇₁BM and EQE spectra^[32]; (b) absorption spectra of each component in the active layer of P3HT∶PTB7-Th∶BEH∶F₆TCNNQ and EQE spectra^[72]; (c) schematic working mechanism and EQE spectra of narrow response PM-OPDs based on CIN and EDN^[73]

Fig. 9. Narrow response PM-OPDs based on optical-microcavity. (a) Device structure, working mechanism, and EQE spectra^[74]; (b) schematic diagram of narrow response PM-OPDs coupled with optical-microcavity^[75]

Fig. 10. PM-OPDs with tunable spectral response range under top/bottom light illumination^[33]. (a) Schematic structure and transmittance spectra of semitransparent Al films; (b) trapped electron distribution on the cross-section of active layers; (c) EQE spectra under different biases

Fig. 11. PM-OPDs with tunable spectral response range under forward/reverse biases. (a) Schematic structure and EQE spectra of device structure ITO/PFN-OX/P3HT∶PTB7-Th∶PC₆₁BM/Al^[79]; (b) schematic diagram, absorption spectra, and responsivity spectra of each layer of device structure ITO/PFN-Br/P3HT∶PCBM/P3HT/P3HT∶PTB7 Th∶PCBM/Al^[80]; (c) schematic diagram, trapped electron distribution, and D^* spectra of device structure ITO/PDIN/poly-TPD∶Y6/MoO₃/P3HT∶PCBM/Al^[81]