Tin-based perovskite and organic additives boost memory for devices

Researchers have long been searching for alternatives to lead-based perovskites for use in electronic devices due to concerns about toxicity and performance limitations. Tin-based perovskites offer a promising solution, but they also present their own challenges, particularly the instability caused by tin oxidation and the difficulty of forming defect-free films.

In this study, published in Advanced Functional Materials, scientists developed a new strategy to enhance the performance and stability of tin-based perovskite transistors by incorporating porphyrin-like additives.

The research team focused on two additives: H₂Pc and SnPc, both belonging to the phthalocyanine family. These molecules are renowned for their strong chemical stability and ability to interact with metal ions. When added to perovskite precursor solution, they help suppress the oxidation of tin ions and improve overall film quality.

As a result, the transistors exhibited significantly higher charge mobility (up to 4.40 cm² V⁻¹ s⁻¹) and improved resistance to environmental degradation. The additives also increased grain sizes and reduced defects, which are critical for efficient charge transport.

In addition to improving transistor performance, the devices also demonstrated fast and stable photomemory behavior. When exposed to light of different wavelengths, the transistors can maintain their memory state even after extremely short pulses (as short as 0.001 seconds). This nonvolatile memory effect opens exciting possibilities for neuromorphic computing, where devices mimic the way the human brain processes and stores information.

“This work demonstrates how molecular engineering can unlock new functionalities in emerging materials,” said Prof. Chu-Chen Chueh, the study’s corresponding author.