Photoluminescence topography of sulfur doped 2" InP grown by the vertical gradient freeze technique

S-doped InP crystals were grown in a VGF furnace. The substrates, cut from the seed, middle and tail portions of the ingot, were investigated by Hall-measurement, photoluminescence spectroscopy and topography. The photoluminescence intensity across the wafer area is very homogeneous, with an average standard deviation of 6% only. The carrier concentration is measured by evaluating the position of the high-energy cut-off of the band-to-band luminescence. The optical data satisfactorily correlate with Hall measurements.