Doping superlattices (

nipi

structures) have been grown in InP using organometallic vapor phase epitaxy in an atmospheric pressure reactor using trimethylindium and phosphine. The unintential doping levels in InP employed in these experiments were as low as 8×10

13

cm

-3

and 300K mobilities as high as 5744cm

2

/V·s. The

n

- and

p

- type dopants were diethyltel-lurium and dimethylzinc

respectivly

both

n

-

p

- carrier concentritions can be up to 10

19

cm

-3

. Such structures have been characterized using low temperature photoluminescence at various excitation intensities

time decay

time resolved photoluminescence

and photo-reflectance experiments. The 4K photoluminescence spectra at various excitation intensities are presented for a structure consisting of six 200Å layers with doping levels of 1×10

18

and 2×10

18

cm

-3

for the

n

- and

p

-layers. The luminescence peak is found to occur at energies considerable less the band gap of InP and to move to higher energies with increased excitation intensity

as expected for doping superlattices where the band gap

which is indirect in real space

increases with increasing excited carrier concentration. The total photoluminescence signal decays in several steps

each exponential

with time constants ranging from 6×10

-8

to 7×10

-4

seconds at 4K.Typical of these spatially indirect band gap materials. Quantum size effects existing in InP doping superlattices have also been probed with photo-reflectance technique. All experimental results are in good agreements with model calculations

which assume a parabolic well to describe the quantum size effects in InP doping superlattices.