Ultralow energy consumption conjugated polymers with perovskite quantum dots <i>via</i> polarity adjustment for photosynaptic transistors

Heterojunction-based photosynaptic transistors have gained significant attention in neuromorphic electronics due to their ease of integration and optical communication capabilities. However, achieving efficient photogenerated carrier transfer within heterojunctions remains a critical challenge in devices utilizing organic and photosensitive materials. This study demonstrates that tuning the bipolarity of perovskite quantum dots (PeQDs) through Sn doping effectively modulates electron and hole trapping properties in conjugated polymer (CP)-PeQD nanocomposites, paving the way for energy-efficient neuromorphic electronics. Optimal Sn doping enhanced PeQDs' photoluminescence quantum yield and adjusted energy levels, promoting efficient electron trapping in p-type devices while reducing hole trapping in n-type systems. Integrating Sn-PeQDs with p-type CPs (diketopyrrolopyrrole-selenophene) enabled exceptional photosynaptic behaviors, such as short-term and long-term plasticity and spike-dependent plasticity. Remarkably, p-type CPs/Sn-PeQDs with optimal Sn doping achieved ultralow energy consumption of 0.169 aJ at a drain voltage of -0.1 mV with a 1 ms light pulse, significantly outperforming earlier p-type optoelectronic synapse designs. This work underscores the potential of Sn-PeQDs as a robust strategy for designing efficient, low-energy neuromorphic systems for next-generation electronics.