Urbach tail studies by luminescence filtering in moderately doped bulk InP.

The shape of the photoluminescence line registered from a side edge of InP wafer is studied as a function of the distance from the excitation spot. The observed redshift in the luminescence maximum is well described by radiation filtering and is consistent with the absorption spectra. Our method provides an independent and accurate determination of the Urbach tails in moderately doped semiconductors. [ABSTRACT FROM AUTHOR]