Interlayers for Charge Transfer-Mediated Triplet Exciton Transfer from a Singlet Exciton Fission Material to An Inorganic Semiconductor

Compositions and mechanisms for the transfer of spin-triplet excitons from a singlet exciton fission material (e.g., tetracene) to an inorganic semiconductor (e.g., n-doped silicon) are provided. The compositions include one or more interlayers, including a charge transfer interlayer (e.g., zinc phthalocyanine), and, optionally, a passivation interlayer (e.g., hafnium oxide, HfO2). The triplet transfer mechanism proceeds via the formation of a charge transfer intermediate state. The transition to the intermediate state is energetically favored by strategically positioned HOMO and/or LUMO levels of the charge transfer interlayer between the singlet fission layer and the inorganic semiconductor. The intermediate state is formed through a transition of either the electron or the hole of the triplet exciton in the charge transfer interlayer (depending, at least in part, on the relative positions of the energy levels) to the conduction or valence band of the inorganic semiconductor, respectively. Methods of forming the compositions are also disclosed.