Ultrafast laser based hybrid methodology of silicon microstructure fabrication for optoelectronic applications

Silicon‐Based Inorganic–Organic Hybrid Nanocomposites for Optoelectronic Applications

“…This methodology can also be applied to p‐type silicon (low emitting) as well. Although the rate of electrochemical etching of p‐type silicon is much faster than for n‐type silicon, which can be etched under controlled conditions to obtain the desired thicknesses (wavelength ordered) and a wide range of porosities (40–89 %), p‐type silicon has been well established as a potential passive material for fabricating a wide range of multilayer photonic structures (such as distributed Bragg reflectors (DBRs), microcavities, or Fibonacci structures) Such photonic structures can be used in many optoelectronic applications such as sensors, LEDs, solar cells. Similarly, this report was only performed for one of the 2D IO perovskites (CHPI), but this method can be easily extended to a range of 2D (R‐MX 4 type) and 3D perovskites (R‐MX 3 type) as the intercalation chemistry is essentially the same .…”

“…It has to be noted that the n-type PS was chosen intentionally to be able to monitor its strong photoluminescence for visualizationp urposes.T his methodology can also be applied to p-type silicon (low emitting) as well. Although the rate of electrochemical etching of p-type silicon is much faster than for n-type silicon, [24,27] which can be etched under controlled conditions to obtain the desired thicknesses (wavelength ordered)a nd aw ide range of porosities (40-89%), p-type silicon has been well established as ap otential passive material for fabricating aw ide range of multilayer photonic structures (such as distributed Bragg reflectors (DBRs),m icrocavities, or Fibonaccis tructures) [18,24,28,29] Such photonics tructures can be used in many optoelectronic applications such as sensors, LEDs, solar cells.S imilarly,t his report was only performed for one of the 2D IO perovskites (CHPI), but this method can be easily extended to ar ange of 2D (R-MX 4 type) and 3D perovskites (R-MX 3 type) as the intercalation chemistry is essentially the same. [19,30] Nevertheless,t he demonstrated nanocomposites and thep roposed methodologyc an used numerous optoelectronic applications.F or example,e xisting well-establisheds ilicon-based solar-cell technologies can be readily combinedw ith perovskite-based technology-either as an ew type of dye-sensitized solar cell (DSSC,P Si nt he place of TiO 2 )o rs imply as ap erovskite-silicon tandem cell.…”

Real-time dynamic evolution monitoring of laser-induced exciton phase flips in 2D hybrid semiconductor (C12H25NH3)2PbI4

“…18 During high intensity infrared pulse interactions, structural modifications can also take place through nonlinear optical processes via multiphoton absorption, tunneling, and avalanche ionization. 19,21 In this work, we demonstrate in situ laser-induced exciton photoluminescence (PL) changes in the naturally self-assembled [(C n H 2n + 1 NH 3 ) 2 PbI 4 ; n = 12, hereafter C12PI] IO hybrids. A series of linear and nonlinear steady-state and time-resolved PL studies of exciton phase-induced flip are presented in a systematic fashion.…”

“…18,19 Upon continuous wave (CW) resonant excitation (in the absorbing region, ћω ≥ E g ), along with typical linear band-to-band electron excitation, the irradiation further causes local heating and ablation effects, 20 whereas in the case of pulsed laser excitation, per pulse energy/intensity is extremely high enough to produce various nonlinear absorption effects such as saturation of absorption and exciton-exciton annihilation. 18,19 In such cases, the absorption coefficient of the medium follows a nonlinear expression α = α 0 + βI, where β is the thirdorder nonlinear absorption coefficient. 18,19 At relatively higher intensities, the laser-induced localized temperatures rapidly increase, thus causing structural deformation as well.…”

“…18,19 In such cases, the absorption coefficient of the medium follows a nonlinear expression α = α 0 + βI, where β is the thirdorder nonlinear absorption coefficient. 18,19 At relatively higher intensities, the laser-induced localized temperatures rapidly increase, thus causing structural deformation as well. [21][22][23][24] On the other hand, with infrared high intensity laser excitation (nonresonant condition), two-photon induced absorption (2PA) is the dominant observed third-order nonlinear process, in which electrons in the valence band can absorb two (or more) low energy photons (2ћω ≥ E g ) simultaneously and make an electronic transition to the conduction band and subsequently the relaxation of the electron resulting in the emission of a photon with a frequency greater than that of absorbed photons.…”