Integrating Unexpected High Charge-Carrier Mobility and Low-Threshold Lasing Action in an Organic Semiconductor

Integrating high charge-carrier mobility and low-threshold lasing action in an organic semiconductor is crucial for the realization of an electrically pumped laser, but remains a great challenge. Herein, we present an organic semiconductor, named as 2,7-di(2-naphthyl)-9H-fluorene (LD-2), which shows an unexpected high charge-carrier mobility of 2.7 cm(2) V-1 s(-1) and low-threshold lasing characteristic of 9.43 mu J cm(-2) and 9.93 mu J cm(-2) and high-quality factor (Q) of 2131 and 1684 at emission peaks of 420 and 443 nm, respectively. Detailed theoretical calculations and photophysical data analysis demonstrate that a large intermolecular transfer integral of 10.36-45.16 meV together with a fast radiative transition rate of 8.0x10(8) s(-1) are responsible for the achievement of the superior integrated optoelectronic properties in the LD-2 crystal. These optoelectronic performances of LD-2 are among the highest reported low-threshold lasing organic semiconductors with efficient charge transport, suggesting its promise for research of electrically pumped organic lasers (EPOLs).

Automated summary

This research presents an organic semiconductor material LD-2 with high charge-carrier mobility and low-threshold lasing characteristics, as well as a high-quality factor. Theoretical calculations and experimental data analysis indicate that the superior optoelectronic properties of LD-2 crystal are attributed to the large intermolecular transfer integral and fast radiative transition rate.