NOVELTY - Compound (I) comprising a metal center and a ligand coordinated to the metal center, is new, where the ligand is substituted 4-phenyl-pyridine compound (a), substituted pyrido(2,1-a)isoquinolinylium compound (b), substituted 2-phenyl-pyridinium compound (c), substituted 1-phenyl-pyridine compound (d), substituted (1,2')bipyridinyl compound (e), substituted 3-phenyl-1,2-dihydro-pyridine compound (f), or substituted 1-phenyl-1,2-dihydro-pyrimidine compound (g).    USE - (I) is useful in an organic light emitting device (claimed), organic phototransistors, organic solar cells and organic photodetectors.    ADVANTAGE - (I) can emit light throughout the visible spectra, including saturated blue emission, in a stable manner.    DETAILED DESCRIPTION - Compound (I) comprising a metal center and a ligand coordinated to the metal center, is new, where the ligand is substituted 4-phenyl-pyridine compound of formula (a), substituted pyrido(2,1-a)isoquinolinylium compound of formula (b), substituted 2-phenyl-pyridinium compound of formula (c), substituted 1-phenyl-pyridine compound of formula (d), substituted (1,2')bipyridinyl compound of formula (e), substituted 3-phenyl-1,2-dihydro-pyridine compound of formula (f), or substituted 1-phenyl-1,2-dihydro-pyrimidine compound of formula (g).    R1, R2=H, alkyl, alkenyl, alkynyl, aralkyl, CN, CF 3, CO 2R1a, C(O)R1a, C(O)NR1a2, NR1a2, NO 2, OR1a, SR1a, SO 2, SOR1a, SO 3R1a, halo, aryl, heteroaryl (both optionally substituted) or a heterocyclic;    R3=H, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, aryl (both optionally substituted) or a heterocyclic group, where additionally or alternatively two R groups on the same or adjacent ring, together forms 5 or 6-member cyclic group, preferably cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl (all optionally substituted by J); either    J=R1a, CN, CF 3, C(O)OR1a, C(O)R1a, C(O)NR1a2, NR1a2, NO 2, OR1a, SR1a, SO 2, SOR1a, or SO 3R1a; or    JJ=fused 5- or 6-membered aromatic group;    R1a=H, halo, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl or heteroaryl;    a=0-4; and    b=0-3.    An INDEPENDENT CLAIM is also included for an organic light emitting device comprising: an anode (115); a cathode; and an organic layer between the anode and the cathode, where the organic layer comprises (I).    DESCRIPTION OF DRAWING(S) - The figure shows the organic light emitting device.    Substrate (110)    Anode (115)    Hole injection layer (120)    Hole transport layer (125)    Electron blocking layer (130)