TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The ionic compound is of formula: M(power)(m'+)aX'(power)(n'-)b.M(power)(m'+)=metal cation;X'(power)(n'-)=anion;anda,b=1 or more.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The conjugated compound is an aromatic compound. The content of conjugated compound in silver-conjugated-compound complex composition is 1 wt.% or more. The silver-conjugated-compound complex composition further contains non-conjugated compound. The conjugated compound contains hetero atom. The conjugated compound has aromatic group of formula: -Ar1-(R1-(X1)m1)n1 (I) and/or aromatic group-containing repeating unit of formula: -Ar2(-(R2-(X2)m2)n2)- (II). The formula weight of aromatic group-containing repeating unit (II) is more than 3x 102.Ar1=(n1+1)-valent aromatic group, preferably residue obtained by removing H directly bonded to carbon of ring of aromatic compound chosen from 57 aromatic compounds e.g. naphthalene, 9H-fluorene, pyridine, 1,3,5-triazine, 9H-carbazole, quinoline, isoquinoline, quinoxaline, acridine or phenazine (all optionally substituted);R1=single bond or (m1+1)-valent group;X1,X2=group containing hetero atom, preferably hydroxy, carboxy, cyano, amino -P(=O)(OH)2, sulfo, monovalent heterocyclyl, -COOM, -SO3M, -NR3M', -O-(R'O)m-R" or group of formula (i);R'=optionally substituted bivalent hydrocarbyl;R"=-NRc, H, optionally substituted monovalent hydrocarbyl, carboxy, sulfo, hydroxy, -SH, cyano or -C(=O)NRc2;Rc=1-30C alkyl or 6-50C aryl (both optionally substituted);R"'=optionally substituted trivalent hydrocarbyl;M=metal cation or optionally substituted ammonium cation;M'=anion;m1,n1,m2,n2=1 or more;Ar2=(n2+2)-valent aromatic group, preferably residue obtained by removing H directly bonded to carbon of ring of aromatic compound chosen from 57 aromatic compounds e.g. naphthalene, 9H-fluorene, pyridine, 1,3,5-triazine, 9H-carbazole, quinoline, isoquinoline, quinoxaline, acridine or phenazine (all optionally substituted);andR2=single bond or (m2+1)-valent group.Preferred Properties: The silver-conjugated-compound complex has Feret diameter of 1100 nm or less. The silver-conjugated-compound complex composition has ratio of number of component of hetero atom (excluding silver atom) in complex, and number of components of all atoms in complex is 0.01 or more measured by X-ray photoelectron spectroscopy. The band gap of conjugated compound with ultraviolet, visible and near-infrared spectroscopy apparatus is 2.10 eV or more. The ionization potential of conjugated compound calculated by optoelectronic spectroscope in air is 5.20 eV or more.