{'fraction_non_alphanumeric': 0.018867924528301886, 'fraction_numerical': 0.006792452830188679, 'mean_word_length': 5.63, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Efficient radiative and nonradiative energy transfer from proximal CdSe/ZnS nanocrystals into silicon nanomembranes.

We demonstrate efficient excitonic sensitization of crystalline Si nanomembranes via combined effects of radiative (RET) and nonradiative (NRET) energy transfer from a proximal monolayer of colloidal semiconductor nanocrystals. Ultrathin, 25-300 nm Si films are prepared on top of insulating SiO(2) substrates and grafted with a monolayer of CdSe/ZnS nanocrystals via carboxy-alkyl chain linkers. The wet chemical preparation ensures that Si surfaces are fully passivated with a negligible number of nonradiative surface state defects and that the separation between nanocrystals and Si is tightly controlled. Time-resolved photoluminescence measurements combined with theoretical modeling allow us to quantify individual contributions from RET and NRET. Overall efficiency of ET into Si is estimated to exceed 85% for a short distance of about 4 nm from nanocrystals to the Si surface. Effective and longer-range radiative coupling of nanocrystal's emission to waveguiding modes of Si films is clearly revealed. This demonstration supports the feasibility of an advanced thin-film hybrid solar cell concept that relies on energy transfer between strong light absorbers and adjacent high-mobility Si layers.