具有分离门电抽运石墨烯中电子-空穴等离子体的冷却效应

Effect of cooling of electron-hole plasma in electrically pumped graphene layer structures with split gates

本文研究了室温条件下具有分离门的电诱导石墨烯n-i-p结构中,与电子和空穴注入有关的粒子数反转效应.考虑n区横向电场的屏栅效应,计算了电子-空穴的有效温度与门电压以及光声子的有效温度与门电压的关系,结果表明注入可以导致n区中电子-空穴等离子体显著冷却,直至低于晶格温度;计算了电流-电压特性以及与频率有关的动态电导率,在一定的电压下,动态电导率在太赫兹频段可以为负值.研究表明电子-空穴等离子体冷却能够加强负动态电导率效应,提高实现太赫兹激射的可行性.

We have studied the effect of population inversion associated with the electron and hole injection in graphene layer n-i-p structures with split gates at room temperature. Considering the transverse electric field screening of the n-section, we calculated the dependence of the electron-hole effective temperature and optical phonon effective temperature on the gate-voltage. It is shown that the injection can lead to cooling of the electron-hole plasma in n-section to the temperatures lower than the lattice temperature. The current-voltage characteristics, and the frequency-dependent dynamic conductivity are calculated, the frequency-dependent dynamic conductivity can be negative in the terahertz frequency range at a certain applied voltage. The study demonstrates that electron-hole plasma cooling can enhance the negative dynamic conductivity effect and improve the feasibility of terahertz lasing.