Near-infrared harvesting transparent luminescent solar concentrators with engineered stokes shift

A luminescent solar concentrator device comprising:

• a waveguide including,
• a luminophore in an active region of the waveguide, having a polymethine component, the polymethine component comprising a plurality of methine groups (═CH—)
• where n is an odd integer greater than 1 and a hydrogen atom (H) of one of the plurality of methine groups is replaced by one of
• where:
• A is selected from nitrogen (N), phosphorus (P), arsenic (As) and antimony (Sb) and D is selected from oxygen (O), sulfur(S), selenium (Se), and tellurium (Te),
• R1 and R2 are independently selected from H, aromatic groups, aliphatic groups bound to A through a carbon atom, or R1 and R2 together form an alicyclic ring containing A, and
• R3 is selected from H, aliphatic groups, aromatic groups, and alicyclic groups bound to D through a carbon atom,
• wherein the luminophore has an overlap integral (OI) of less than or equal to about 20, and an absolute absorption of greater than or equal to about 50% in absorption spectra, wherein the OI is defined by formula (2):
• OI
• =
• ∫
• 0
• ∞
• A
• ⁡
• (
• λ
• )
• ·
• PL
• *
• (
• λ
• )
• ⁢
• d
• ⁢
• λ
• ,
• (
• 2
• )
• where A(λ) is a single-path absolute absorption spectrum of a composite film comprising a luminophore and a host material, and PL*(λ) is a normalized emission spectrum of the luminophore in the host material,
• wherein the active region of the waveguide includes a front surface and a back surface, the front surface and the back surface being outermost surfaces of the luminescent solar concentrator device, and
• wherein the luminescent solar concentrator device is visibly transparent and has a quantum yield of greater than or equal to about 20%.