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Neodymium-doped hydrogenated amorphous silicon sub-nitrides a-SiN
x
:H〈Nd〉 thin films were deposited by rf-sputtering using a Si target partially covered by metallic Nd chips and Ar+N
2+H
2 sputtering gas. Characteristic Nd
3+ near infra-red (NIR) photoluminescence (PL) was detected between 10 and 300
K with peaks at ∼935, ∼1090 and ∼1390
nm, corresponding to the intra-4f transitions
4
F
3/2→
4
I
9/2
,
4
F
3/2→
4
I
11/2
and
4
F
3/2→
4
I
13/2
, respectively. Measurements using different excitation wavelengths indicate that the Nd
3+ excitation occurs through the a-SiN
x
:H matrix. Varying the nitrogen content
x from 0 to nearly 1.3 increases the matrix bandgap. The PL efficiency is maximum when the bandgap corresponds to twice the
4
F
3/2→
4
I
9/2
transition, indicating a defect-related energy transfer mechanism. The temperature quenching can be as low as less than a factor 3 between 10 and 300
K for 2.8
eV gap samples. Thermal annealing can enhance the PL intensity by a factor 10. Neodymium concentrations above ∼3×10
20 atoms/cm
3 slightly reduce the PL intensity probably due to excess of inactive defect centers. Along with erbium-doped amorphous silicon alloys, a-SiN
x
:H〈Nd〉 can be used in the development of photonic devices in the future.