Relaxation Behavior of Excited Small Molecules Doped in Rare Gas Crystals and Clusters

本研究的目的是研究掺杂在稀有气体和/或N_2晶体中的小分子在光子吸收后的弛豫行为。取得了以下结果。1.观察到O_2和N_2分子及原子物种的激发发射光谱。2.在低温Ar晶体中稀释O_2分子的情况下，观察到短寿命的c-α发射，特别是v '= 5能级的c-α发射和A'-X发射沿着。3.在低温N_2晶体中掺杂O_2分子时，观察到两个发射带系，一个是从A'态的v'= 1能级到X态，另一个是从c态的v '= 0能级到a态，与激发波长无关。4.用248 nm的准分子激光辐照低温N_2晶体，观察到氮原子的^2D激发态发射。结果表明，N_2分子通过双光子过程被激发，弛豫到A态，然后将激发能转移到基态的氮原子上，产生激发态的氮原子。5.总之，O_2和N_2分子通过单光子和多光子吸收可以产生各种激发态，并且发现一些激发态可以在晶体中长期储存。

The purpose of the present study is to investigate the relaxation behavior of small molecules doped in rare gas and/or N_2 crystals following the photon-absorption. The following results have been obtained. 1. The emission spectra from excited O_2 and/or N_2 molecules and atomic species were observed. 2. In the case of O_2 molecules diluted in a low-temperature Ar crystal, short lived c-a emissions, particlarly from the v'=5 level were observed along with the A'-X emissions. 3. In the case of O_2 molecules doped in a low temperature N_2 crystal, two emission band systems, one from the v'=1 level of A' state to X state, and the other from the v'=0 level of c state to a state were observed, independent on the excitation wavelength. 4. When a low temperature N_2 crystal was irradiated by a focused excimer laser at 248 nm, the emission from the ^2D excited state of atomic nitrogen was observed. It was concluded that N_2 molecules are excited via two-photon process and relax to A state and then transfer the excitation energy to the ground state atomic nitrogen to yield the excited nitrogen atoms. 5. In summary, various excited states of O_2 and N_2 molecules could be produced via one-and multiple-photon absorption and some excited apecies were found to be stored in the crystal for a long time.