Perovskites, especially Pb-free tin halide perovskites, show promise for efficient optoelectronic/electronic microsystems and image sensors, fabricated through simple techniques like inkjet printing. This approach aims to reduce device costs globally, cater to various applications, and decrease reliance on current semiconductor technologies. In this work we anticipated innovations with 2D and 2D/3D tin halide perovskites which have the potential to become commercially viable products, addressing the evolving needs of a digital society while promoting sustainability and reducing dependence on existing semiconductor technologies.

Along the work we have proposed and tested experimentally (chemical synthesis and basic structural and optical properties) many perovskite and perovskite-like materials. From them, we focused on several of them: i) 2D/3D perovskite compounds (R0.5,BA0.5)2FA9Sn10I31 with  R = PEA, TEA, DIP cations for allowing crystallization and stabilize the tin-perovskite phase for inkjet printing deposition techniques; ii) FASnI3  with additives and light soaking was further used for spin-coated films used in the optimization of vertical lasing structures;  iii) PEA2SnI4SnI4 and TEA2SnI4 for red emitting LEDs and photonics (emitting devices and photodetectors); Cs3Cu2Cl5 and Rb3InCl6:Sb for blue and green LEDs.

In photovoltaic devices, important advances were achieved: world record efficiency for flexible lead-free perovskite solar modules of 5.7 % under 1-sun and an impressive 9.4% for 2000 lx, indicating their potential for indoor applications. This was possible through the in-situ synthesis of SnI2 from metallic tin and iodine in a DMF:DMSO solvent.

For lead-free LEDs: (i)-(ii) First inkjet-printed Pb-free perovskite LED emitting at red wavelengths and first on a flexible substrate with commom DMF and sustainable DMSO solvents.

In photonics applications several advances were achieved: (i) ASE/lasing action and near single-mode operation were observed over a threshold of 200 µJ/cm2 for inkjet-printed films of 2D/3D G-LFPs, which is close to that obtained with the counterpart device implemented with the 3D FASnI3 film deposited by spin-coating; (ii) This 2D/3D G-LFPs also exhibits good performances for low-level light photodetection: responsivity as high as 50 A/W was measured after one month at 450 nm in encapsulated devices, with an estimated (using dark current value) detectivity better than 8.1010 Jones; flexible photodetectors exhibit comparable performances. (iii) inkjet-printed films of 2D tin-perovskites (TEA2SnI4 among them) are exhibiting efficient two photon absorption mechanism at room temperature and also leading to efficient photodetectors in glass and PET substrates with very low dark currents.

The proposed eco-friendly devices should be taken into account in future advances for scalable flexible optoelectronic Sn-based applications.