Abstract
CsPbBr3 is a direct-gap semiconductor where optical absorption takes place across the fundamental bandgap, but this all-inorganic halide perovskite typically exhibits above-bandgap emission when excited over an energy level, lying above the conductionband minimum. We probe this bandgap anomaly using wavelength-dependent multiphoton absorption spectroscopy and find that the fundamental gap is strictly twophoton forbidden, rendering it three-photon absorption (3PA) active. Instead, two-photon absorption (2PA) commences when the two-photon energy is resonant with the optical gap, associated with the level causing the anomaly. We determine absolute nonlinear optical dispersion over this 3PA-2PA region, which can be explained by two-band models in terms of the optical gap. The polarization dependence of 3PA and 2PA is also measured and explained by the relevant selection rules. CsPbBr3 is highly luminescent under multiphoton absorption at room temperature with marked polarization and wavelength dependence at the 3PA-2PA crossover and therefore has potential for nonlinear optical applications.
| Original language | English |
|---|---|
| Pages (from-to) | 4912-4917 |
| Number of pages | 6 |
| Journal | Journal of Physical Chemistry Letters |
| Volume | 8 |
| Issue number | 19 |
| DOIs | |
| Publication status | Published - Jan 1 2017 |
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ASJC Scopus subject areas
- Materials Science(all)
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Multiphoton absorption order of CsPbBr3 as determined by wavelength-dependent nonlinear optical spectroscopy. / Saouma, Felix O.; Stoumpos, Constantinos C.; Kanatzidis, Mercouri G; Kim, Yong Soo; Jang, Joon I.
In: Journal of Physical Chemistry Letters, Vol. 8, No. 19, 01.01.2017, p. 4912-4917.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Multiphoton absorption order of CsPbBr3 as determined by wavelength-dependent nonlinear optical spectroscopy
AU - Saouma, Felix O.
AU - Stoumpos, Constantinos C.
AU - Kanatzidis, Mercouri G
AU - Kim, Yong Soo
AU - Jang, Joon I.
PY - 2017/1/1
Y1 - 2017/1/1
N2 - CsPbBr3 is a direct-gap semiconductor where optical absorption takes place across the fundamental bandgap, but this all-inorganic halide perovskite typically exhibits above-bandgap emission when excited over an energy level, lying above the conductionband minimum. We probe this bandgap anomaly using wavelength-dependent multiphoton absorption spectroscopy and find that the fundamental gap is strictly twophoton forbidden, rendering it three-photon absorption (3PA) active. Instead, two-photon absorption (2PA) commences when the two-photon energy is resonant with the optical gap, associated with the level causing the anomaly. We determine absolute nonlinear optical dispersion over this 3PA-2PA region, which can be explained by two-band models in terms of the optical gap. The polarization dependence of 3PA and 2PA is also measured and explained by the relevant selection rules. CsPbBr3 is highly luminescent under multiphoton absorption at room temperature with marked polarization and wavelength dependence at the 3PA-2PA crossover and therefore has potential for nonlinear optical applications.
AB - CsPbBr3 is a direct-gap semiconductor where optical absorption takes place across the fundamental bandgap, but this all-inorganic halide perovskite typically exhibits above-bandgap emission when excited over an energy level, lying above the conductionband minimum. We probe this bandgap anomaly using wavelength-dependent multiphoton absorption spectroscopy and find that the fundamental gap is strictly twophoton forbidden, rendering it three-photon absorption (3PA) active. Instead, two-photon absorption (2PA) commences when the two-photon energy is resonant with the optical gap, associated with the level causing the anomaly. We determine absolute nonlinear optical dispersion over this 3PA-2PA region, which can be explained by two-band models in terms of the optical gap. The polarization dependence of 3PA and 2PA is also measured and explained by the relevant selection rules. CsPbBr3 is highly luminescent under multiphoton absorption at room temperature with marked polarization and wavelength dependence at the 3PA-2PA crossover and therefore has potential for nonlinear optical applications.
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U2 - 10.1021/acs.jpclett.7b02286
DO - 10.1021/acs.jpclett.7b02286
M3 - Article
VL - 8
SP - 4912
EP - 4917
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
SN - 1948-7185
IS - 19
ER -