Fig. 1. Chemical structure of biphenyl skeleton

Fig. 2. Molecular structure of biphenyl derivatives linked by carbon-carbon single bonds

Fig. 3. Molecular structure of biphenyl derivatives linked by carbon-carbon double bonds

Fig. 4. Novel nonheterostructure OLED based on BSBCz^[32-34]. (a) Energy level diagrams for OLEDs with a single emitter layer of BSBCz, OLEDs with a hole-blocking BCP layer, and OLEDs with electron-blocking mCP and hole-blocking BCP layers from top to bottom; (b) current density-voltage characteristic curves of devices A, B, and C; (c) exciton density (η_exciton)-current density characteristic curves of devices A, B, and C

Fig. 5. Characteristics of OLET devices based on DBTVB^[55]. (a) Energy-level alignment of OLET device; (b) schematic diagram of OLET device; (c) summary map of single-component high-performance OLET devices reported so far; (d)-(e) transfer and output curves under P-type operation mode; (f)-(g) transfer and output curves under N-type operation mode

Fig. 6. Organic micro/nao-crystal lasers based on biphenyl derivatives. (a) High-resolution PL spectrum and image of laser emissions at 475 nm of BPVT; (b) high-resolution PL spectrum and image of laser emissions at 541 nm of BBTVB; (c) high-resolution PL spectrum and image of laser emissions at 588 nm of BTTVB; (d)-(e) schematic illustration and lasing spectra of dual-wavelength switchable vibronic laser; (f) normalized lasing spectra and PL images of BP3T doped BP1T microcrystals

Fig. 7. CW pumped lasers^[65]. (a) Schematic representation of mixed-order DFB grating structure; (b) streak camera images showing laser oscillations from a representative BSBCz:CBP encapsulated mixed-order DFB device at repetition frequency from 0.01 to 80 MHz; (c) streak camera images showing laser emission integrated over 100 pulses from an encapsulated mixed-order DFB device using a BSBCz:CBP (20%∶80%) film as gain medium and optically pumped by pulses of 30 ms and 2.0 kW/cm² (top) or 800 ms and 200 W/cm² (bottom); (d) photograph of DFB device operating in long-pulse regime (excitation, 30 ms)

Fig. 8. Polariton lasers based on DSA derivatives^[75-76]. (a) Polariton emission of DPAVBi microcavity when laser energy is less than threshold^［75］; (b) polariton emission of DPAVBi microcavity when laser energy is more than thrshold^［75］; (c) polaritons start to occupy high-energy discrete levels at large angles^［75］; (d) polariton emission BSBCz-EH microcavities when laser energy is less than threshold and more than threshold^[76]

Fig. 9. Indication of current-injection lasing^[36,44]. (a) Schematic representation of organic semiconductor laser diodes (OSLD)^[36]; (b) SEM images of DFB grating and cross-section SEM image of OSLD^[36]; (c) emission spectra and threshold of BSBCz OSLDs^[36]; (d) DFB- and FRP-el-OSCL devices in electrically driven mode operation and laser emission based on BP3T microcrystals^[44]; (e) intensity of emission as a function of current density or light fluence^[44]; (f) comparison of relationship of intensity of emission versus light fluence between ASE and laser in optically driven mode^[44]