Text this: AlGaAs optical phonon replicas in the photoluminescence spectra of GaAs layer in an Al0.3Ga0.7As/GaAs heterostructure

  _____     _____    _    _    __   __   ______   
 /  ___||  |  ___|| | || | ||  \ \\/ // |      \\ 
| // __    | ||__   | || | ||   \ ` //  |  --  // 
| \\_\ ||  | ||__   | \\_/ ||    | ||   |  --  \\ 
 \____//   |_____||  \____//     |_||   |______// 
  `---`    `-----`    `---`      `-`'   `------`