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Wavelength tunable photoluminescence (PL) of Si-rich silicon nitride (SRSN) film with buried Si nanocrystals(Si-ncs) grown by plasma enhanced chemical vapor deposition (PECVD) under SiH_4 and NH_3 environmentis investigated.Intense broadband visible emissions tunable from blue to red can be obtained fromthe as-deposited SiN_x thin films with increasing NH_3 flow rate from 150 to 250 sccm and detuning theSiH_4/NH_3 flow ratio during deposition.To date,the normalized PL wavelength of SiN_x films after annealingcould be detuned over the range of 385-675 nm by decreasing the NH_3 flow rate,corresponding to anenlargement on Si-nc size from 1.5-2 to 4-5 nm.The PL linewidth is decreased with increasing ammoniaflow rate due to the improved uniformity of Si-ncs under high NH_3 flow rate condition.In addition,the PLintensity is monotonically increasing with the blue shift of PL wavelength due to the increasing density ofsmall-size Si-ncs.The ITO/SiN_x/p-Si/Al diode reveals highly resistive property with the turn-on voltageand power-voltage slope of only 20 V and 0.18 nW/V,respectively.The turn-on voltage can further reducefrom 20 to 3.8 V by improving the carrier injection efficiency with p-type Si nano-rods.
Wavelength tunable photoluminescence (PL) of Si-rich silicon nitride (SRSN) film with buried Si nanocrystals (Si-ncs) grown by plasma enhanced chemical vapor deposition (PECVD) under SiH_4 and NH_3 environmentis investigated. Intense broadband visible emissions tunable from blue to red can be obtained from the as-deposited SiN_x thin films with increasing NH 3 flow rate from 150 to 250 sccm and detuning the SiH_4 / NH_3 flow ratio during deposition.To date, the normalized PL wavelength of SiN_x films after annealing can be over-ranged 385 -675 nm by decreasing the NH 3 flow rate, corresponding to anenlargement on Si-nc size from 1.5-2 to 4-5 nm. The PL linewidth is decreased with increasing ammonia flow rate due to the improved uniformity of Si-ncs under high NH 3 flow rate condition.In addition, the PL intensity is monotonically increasing with the blue shift of PL wavelength due to the increasing density ofsmall-size Si-ncs.The ITO / SiN_x / p-Si / Al diode reveals highly resistive prope rty with the turn-on voltage and power-voltage slope of only 20 V and 0.18 nW / V, respectively. The turn-on voltage can further reduce from 20 to 3.8 V by improving the carrier injection efficiency with p-type Si nano-rods.