Advertisement

Photoluminescence

  • Yuhei MiyauchiEmail author
Chapter

Abstract

Spontaneous emission (radiation) of light from an electronically excited material (except for thermal radiation) is called “luminescence.” In particular, photoluminescence (PL) is light emission occurring after absorption of shorter-wavelength light (higher-energy photons) (Fox in Optical properties of solids. Oxford University Press Inc 2001 [1]). In a typical direct-gap semiconductor, electrons (solid circles) and holes (open circles) that are optically excited into conduction and valence bands, respectively, first relax to lower available energy levels by emitting multiple low-energy phonons and then relax to the ground state by recombination and emission of a photon (Fig. 77.1, ELaser and EPL are the excitation and emission photon energies, respectively). Since the photoexcited electron and hole are oppositely charged, they can attract each other through mutual Coulomb interaction and form a hydrogen-like electron–hole pair called an “exciton.”

Keywords

Semiconductor Band gap Exciton Imaging Local conditions 

References

  1. 1.
    Fox, M.: Optical properties of solids. Oxford University Press Inc. (2001)Google Scholar
  2. 2.
    Mak, K.F., Shan, J.: Photonics and optoelectronics of 2D semiconductor transition metal dichalcogenides. Nat. Photon 10, 216–226 (2016)CrossRefGoogle Scholar
  3. 3.
    Miyauchi, Y.: Photoluminescence studies on exciton photophysics in carbon nanotubes. J. Mater. Chem. C. 1, 6499–6521 (2013)CrossRefGoogle Scholar
  4. 4.
    Miyauchi, Y., Hirori, H., Matsuda, K., Kanemitsu, Y.: Radiative lifetimes and coherence lengths of one-dimensional excitons in single-walled carbon nanotubes. Phys. Rev. B. 80, 081410(R)/1-081410(R)/4 (2009)Google Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2018

Authors and Affiliations

  1. 1.Institute of Advanced EnergyKyoto UniversityUji, KyotoJapan

Personalised recommendations