title: Biologically inspired band-edge laser action from semiconductor with dipole-forbidden band-gap transition.
abstract: A new approach is proposed to light up band-edge stimulated emission arising from a semiconductor with dipole-forbidden band-gap transition. To illustrate our working principle, here we demonstrate the feasibility on the composite of SnO2 nanowires (NWs) and chicken albumen. SnO2 NWs, which merely emit visible defect emission, are observed to generate a strong ultraviolet fluorescence centered at 387 nm assisted by chicken albumen at room temperature. In addition, a stunning laser action is further discovered in the albumen/SnO2 NWs composite system. The underlying mechanism is interpreted in terms of the fluorescence resonance energy transfer (FRET) from the chicken albumen protein to SnO2 NWs. More importantly, the giant oscillator strength of shallow defect states, which is served orders of magnitude larger than that of the free exciton, plays a decisive role. Our approach therefore shows that bio-materials exhibit a great potential in applications for novel light emitters, which may open up a new avenue for the development of bio-inspired optoelectronic devices.
authors.affiliation: Department of Physics, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Cih-Su
authors.initials: CS
authors.lastname: Wang
authors.affiliation: Department of Physics, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Chi-Shung
authors.initials: CS
authors.lastname: Liau
authors.affiliation: Department of Physics, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Tzu-Ming
authors.initials: TM
authors.lastname: Sun
authors.affiliation: Department of Physics, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Yu-Chia
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung 202, Taiwan.
authors.forename: Tai-Yuan
authors.initials: TY
authors.lastname: Lin
authors.affiliation: Department of Physics, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Yang-Fang
authors.initials: YF
authors.lastname: Chen
mesh_terms: D007834:Lasers; D053770:Nanowires; D012666:Semiconductors; D017971:Tin Compounds
chemical_list: D017971:Tin Compounds; C045358:stannic oxide