NOVELTY - Substrate attached with linker having free reactive group A or monomer (I) having free reactive group is provided. The linker or monomer (I) is contacted with monomer (II) having two identical free reactive groups (B) reactive with A. Monomer (II) couples with monomer (I). The monomer (II) is contacted with monomer (III) having two identical free reactive groups A, and monomer (III) couples with monomer (II) to form an oligomeric molecule attached to substrate.    USE - For forming oligomeric molecule on substrate used in light harvesting array (claimed) (e.g. solar cells), molecular information storage devices, field effect transistors, sensors, and memory chips. The solar cells are used in radios, televisions, computers, processors, calculators, telephones, wireless communication device such as pagers, watches, emergency location device, electric vehicles, emergency power supplies, power generators, lights or lamps, other illuminating device, monitoring device, inspection device, radiation detector, imaging device and optical coupling device.    ADVANTAGE - The novel stepwise synthesis of oligomeric molecules eliminates the use of protecting groups, greatly simplifying the synthesis by eliminating the requirement of the deprotection step between each monomer coupling reaction. Therefore the synthesis cost is reduced and the necessity of identifying deprotection conditions compatible with oligomer and/or underlying substrate is avoided. The step yield is improved, thereby increasing surface density of full length oligomers. The use of oligomeric redox active molecules attached to substrate improves the charge storage density and hence readability of molecular memory.    DETAILED DESCRIPTION - A substrate attached with a linker bearing a free reactive group A or monomer (I) bearing a free reactive group is provided. The linker or monomer (I) is contacted with monomer (II) comprising two identical free reactive groups (B) reactive with A. Monomer (II) couples with monomer (I) via a reaction between A and one of the reactive groups B. The monomer (II) is contacted with monomer (III) comprising two identical free reactive groups A, and monomer (III) couples with monomer (II) via a reaction between one of reactive groups A, and the free reactive group B on the monomer (II), to form an oligomeric molecule attached to the substrate. INDEPENDENT CLAIMS are included for the following:    (1) kit for the assembly of an oligomeric molecule, comprising a container containing monomers (I) of formula: A-M1-A, and monomer (II) of formula: B-M2-B;    (2) a composition comprising an array of electrodes, each comprising a redox-active molecule electrically coupled to an electrode, and the redox-active molecule is an oligomeric molecule synthesized in a stepwise synthesis method;    (3) apparatus comprising a fixed electrode electrically coupled to a storage medium comprising a redox-active molecule synthesized in a stepwise synthesis method; and    (4) a light harvesting array comprising substrate (I) comprising an electrode and a layer of light harvesting rods electrically coupled to the electrode. The light harvesting rods comprise an oligomer of porphyrinic macrocycles coupled to the substrate. The oligomer comprises monomeric units of porphyrinic macrocycles, and the oligomer is synthesized in a stepwise synthesis method.    A,B=free reactive groups selected such that A and B react with each other to form a covalent linkage;    M1,M2=charge storage moiety, charge separation moiety, spacer, electrolyte, or tether.