TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Nanomaterial: The mean distance between optical antenna and energy transfer facilitating transition metal dopants is less than the Forster radius. The energy transfer facilitating transition metal dopants and emitter transition metal dopants are identical elements. The energy transfer facilitating and emitter transition metal dopants are distinct elements, where an emission spectrum of the energy transfer facilitator overlaps with an absorption spectrum of the emitter. The energy transfer facilitating transition metal dopants have concentration 5-20 times greater than concentration of emitter transition metal dopants. The energy transfer facilitating transition metal dopants have a concentration range of 5-30 mol.%, and where the emitter transition metal dopants have a concentration of 0.01-10 mol.%. The transition metal-doped material comprises second emitter transition metal dopants, where the emitter transition metal dopants and second emitter transition metal dopants have distinct emission spectra. The optical nanocrystal comprises second optical antenna bonded to the nanocrystal, where the optical antenna and second optical antenna have distinct absorption spectra, where an absorption spectrum of the energy transfer facilitating transition metal dopants overlaps with a second emission spectrum of the second optical antenna, where the transition metal-doped material comprises second energy transfer facilitating transition metal dopants and second emitter transition metal dopants, where second absorption spectrum of the second energy transfer facilitating transition metal dopants overlaps with an emission spectrum of the second optical antenna, where the emitter transition metal dopants and second emitter transition metal dopants have distinct emission spectra. The optical antenna is part of the ligand layer directly bonded to nanocrystal. The optical antenna is bonded indirectly to nanocrystal via chain linker in the ligand layer. The optical nanomaterial comprises encapsulating layer bonded to the ligand layer. The encapsulating layer comprises an inorganic material or polymer material; further comprises multiple optical antennas bonded to the nanocrystal, where the optical antennas number more than (Ln3+)/ theta epsilon eta , where (Ln3+) is concentration of the sensitizer transition metal dopants, epsilon is an absorptivity of the optical antenna, theta is a predetermined flux of incident photons and eta is a rate of FRET or Dexter energy transfer. The nanocrystal has transmittance of at least 75% in the visible and/or ultraviolet spectrum. The optical antenna has a transmittance of at least 75% in the visible and/or ultraviolet spectrum. The optical antenna has full-width-half-maximum range of absorbance of at least 10 nm in the near infrared spectrum. The optical antenna has an absorption coefficient in the near infrared spectrum of at least 10 L.mol-1.cm-1. The emission spectrum of the emitter transition metal dopants is in the visible spectrum. The nanomaterial is a nanoparticle having a largest width less than 150 nm in extent. The nanomaterial is a nanotube having largest width less than 150 nm in extent. The nanomaterial is nanosheet having thickness less than 150 nm in extent. The nanocrystal comprises homogeneous nanocrystal. The nanocrystal has a phonon energy of at most 1000 cm-1 (i.e. 0.12 eV) and defect density of at most 0.33 defects/cm3. The nanomaterial is nanoparticle, and nanocrystal comprises inner core and outer shell. Preferred Components: The transition metal doped material comprises dopants selected from Nd3+, Er3+, Ho3+, Pr3+, Dy3+, Gd3+, Tm3+, Tm2+, U4+, U3+, Ti2+, Cr3+, Ni2+, Mn2+, Mo3+, Re4+ and Os4+. The energy transfer facilitating transition metal dopants are Yb3+ or Er3+. The emitter transition metal dopants are Er3+, Ho3+ or Tm3+. The energy transfer facilitating dopants are Er3+ or Nd3+ and have concentration of 0.5-30 mol.%. The optical antenna is composed of an inorganic compound selected from Cr3+, Ce3+ and UO2, synthetic organic dye such as nickel dithiolanes, phthalocyanines/naphthalocyanines or arylenes. The outer shell is composed of metal fluoride, metal oxide and metal fluoride mixture, metal oxyfluoride, metal oxide or metal chalcogenide. EXAMPLE - No suitable example is given.