A new one-dimensional Cd-based hybrid halide with face-sharing CdCl 6 octahedral chains exhibited a bright white-light emission upon ultraviolet photoexcitation.
5 June 2017 in The Journal of Physical Chemistry C
Hematite (α-Fe2O3) material has outstanding advantages in the photoelectrochemical water splitting (PEC-WS) field, while its generally low photogenerated-carrier separation (ηsep) and transfer (ηtran) efficiencies severely impede its further application. An internal electric field can significantly enhance ηsep and ηtran efficiencies, but the effective scope urgently needs to be expanded. This work innovatively implements gradient doping into an α-Fe2O3 film to achieve a direction-controlled and full-space internal electric field throughout the entire photoanode. The carrier-transport dynamics and density functional theory (DFT) calculations demonstrate that the direction of the internal electric field of an α-Fe2O3 photoanode with gradient-decreasing doping is consistent with that of the photoanode/electrolyte junction. The synergy effect between them can substantially enhance the photogenerated-carrier separation and transfer efficiency. Compared with the case of gradient-increasing doping, the α-Fe2O3 photoanode with gradient-decreasing doping exhibits the largest saturated photocurrent density and an enhancement of 40.7% (55.2%) for ηsep (ηtran) at 1.23 VRHE under AM 1.5G illumination. This work provides a facile and general gradient doping strategy to expand the effective scope of an internal electric field for boosting the photoelectric conversion performance.
A new one-dimensional (1D) face-shared hybrid lead bromide of (2cepiH)PbBr3, which exhibits intrinsic broadband yellow-light emission with a quantum yield of 16.8% outperforming all previously reported 1D face-shared hybrid metal halides, is obtained. The origin of broadband emission and the coexistence of free excitons and self-trapped excitons are deeply investigated by variable-temperature photoluminescence spectra. Our work paves the way to discovering more wonderful light-emitting materials.