Observation of enhanced photoluminescence from silicon photonic crystal nanocavity at room temperature

Abstract

We fabricated air-bridge-type silicon photonic crystal (PC) nanocavities and observed significant enhancement of photoluminescence (PL) from crystalline silicon at room temperature. Cavity-resonant peaks shifted toward longer wavelengths when the period of PC was increased and their polarization dependences agree with the calculation. At a cavity mode wavelength, a 310-fold enhancement of PL intensity, compared with that of unpatterned silicon-on-insulator substrate, was demonstrated.

Enhanced 154 μm emission in Y-Er disilicate thin films on silicon photonic crystal cavities

“…This is due to a combination of the increased extraction efficiency given by the presence of the photonic crystal pattern, and the Purcell effect given by the coupling with the cavity modes. We note that this enhancement, is comparable to the best values from L3 PhC cavities reported previously [14,16]. Finally the structure with Δr = + 6 nm exhibits the strongest PL as a result of the best trade-off between the increased vertical coupling and the reduced Q-factor, and we only consider this in the following.…”

“…For example, light emission enhancement in crystalline Si photonic crystal (PhC) cavities was demonstrated as a combination of the Purcell effect and the increase of the extraction efficiency [14][15][16][17]. This approach has also been used successfully to enhance the optical emission of Er atoms by coupling them with photonic crystals [18] and high-Q optical cavity modes, such as microdisks [19] and microtoroids [20,21]; stimulated emission and linewidth narrowing have also been observed [22,23].…”

Enhancement of carbon nanotube photoluminescence by photonic crystal nanocavities

“…The device without nanotubes show Si PL from around 1100 to 1200 nm with a sharp peak near 1190 nm which we assign to the 5th mode of the L3 cavity. 15,24 In comparison, for the device with nanotubes, we observe broad emission for wavelengths longer than 1200 nm with a very sharp peak near 1400 nm and a few more peaks around 1300 nm. The broad emission is consistent with PL from SWCNTs, 8 while the positions of the additional peaks agree with the other modes of the L3 cavity, with the sharpest peak near 1400 nm being the fundamental mode.…”

“…The cavity modes redshift with increasing a, consistent with previous work on Si PL enhancement. 15,24 Such redshifts combined with different modes of the cavity allow tuning throughout the broad spectrum of the nanotube PL.…”

Room-temperature emission at telecom wavelengths from silicon photonic crystal nanocavities

“…10,11 However, their application to increasing light emission from c-Si has been limited to the narrow spectral region of indirect band-edge recombination at 1.1 m wavelength. [12][13][14] In this letter, we report the observation of enhanced room-temperature photoluminescence ͑PL͒ from silicon PhC nanocavities with resonant modes in the range 1.3-1.6 m, well below the Si band gap. The broad sub-bandgap emission feeding the cavity modes is attributed to optically active defects introduced during the manufacturing process of the silicon-on-insulator ͑SOI͒ wafers.…”