Ensemble emission of isolated organic chromophores incorporated into an organometallic single crystal.

Molecular quantum emitters are becoming increasingly important in quantum information and communication. As a stepping stone towards a single-molecule quantum system, the collective emission from the ensemble of isolated organic chromophores, randomly and sparsely incorporated into an organometallic host crystal, is characterized by Raman and temperature-dependent photoluminescence spectroscopies. The tetracene or rubrene guest chromophores are deposited at very low densities when the ferrocene host is grown in a crystalline form, so that each of the chromophores is well isolated by its organometallic molecular neighbors. The ensemble emission of the chromophores is compared to that of the crystalline or dissolved forms to identify its unique spectral features. The enhanced quantum yield and reduced spectral linewidth with a significant blue-shift in photoluminescence suggest that ferrocene is a novel type of host matrix, maximizing the ability of the tetracene guest to act as a well-isolated quantum entity, while suppressing unwanted environmental decoherence by confining it within the ferromagnetic (organometallic) host material.