All-perovskite photovoltaic cells achieve 26.11% PCE with MPPT-verified long-term stability. Learn how EVI₂ dual-function material powers wearable devices via flexible PVB technology.

All-perovskite photovoltaic cells are transforming power solutions for portable wearable devices. Conventional photovoltaic power supply batteries suffer from poor integration and miniaturization — but all-perovskite photovoltaic cells overcome both by using perovskite simultaneously as the light-absorbing layer and cathode. This study introduces a dual-function material sharing strategy via ethyl violete diiodide (EVI₂), pushing all-perovskite photovoltaic cells to a record power conversion efficiency (PCE) of 26.11%. Rigorous maximum power point tracking (MPPT) — the gold-standard MPPT methodology for operational durability — validates exceptional long-term stability: 96.2% retention after 1,000 hours. The integrated all-perovskite photovoltaic battery (PVB) system, confirmed by maximum power point tracking analysis, delivers 24-hour continuous power to a wearable glucose monitor — proving that all-perovskite photovoltaic cells are transitioning from the lab to real-world portable wearable device applications.

Interaction Between EVI₂ and Perovskite

All-perovskite photovoltaic cells are perovskite solar cells (PSCs) where every functional layer, from light absorption to charge storage, leverages perovskite materials. Unlike silicon-based photovoltaics requiring rigid wafers processed at ~1,000°C, perovskite solar cells can be solution-processed at low temperatures on flexible substrates such as PEN and PET films. This dual-function architecture — absorbing sunlight and storing electrochemical energy within a single material platform — eliminates the integration complexity that has historically prevented photovoltaic power supply batteries from powering portable wearable devices.

Photovoltaic Performance of Perovskite Solar Cells (PSCs)

The power conversion efficiency (PCE) of perovskite solar cells has surged from 3.8% (2009) to a certified 26.7% (2024). In this study, the champion all-perovskite photovoltaic cell achieved 26.11% PCE — among the highest reported for single-junction perovskite solar cells. Key metrics: short-circuit current density 26.17 mA cm⁻², open-circuit voltage 1.186 V, and fill factor 84.12%, with negligible hysteresis (<1.1%).

XPS and DFT calculations reveal that EVI₂ increases electron density at Pb atoms on the perovskite surface and induces a favorable conduction band minimum shift, facilitating rapid interfacial charge extraction. The p-i-n structured device employs C₆₀ as the electron transport layer and p-type organic small molecules as the hole transport layer.

EVI₂ forms a surface modification layer rather than altering the bulk structure. KPFM confirms uniform surface potential distribution. Key improvements: PL lifetime doubled from 223.5 ns to 457.4 ns, and trap filling limit voltage (defect density proxy) reduced from 0.56 V to 0.31 V — directly suppressing non-radiative recombination.

Long-term stability is the critical barrier to commercial perovskite solar cells. This study employs maximum power point tracking (MPPT) — the gold standard for operational stability assessment — using AAA-grade LED solar simulators with independently controllable spectral bands (300–400, 400–750, and 750–1200 nm). MPPT continuously tracks peak power output under sustained illumination, simulating real-world deployment far more accurately than dark storage tests.

These maximum power point tracking metrics confirm that all-perovskite photovoltaic cells meet the long-term stability requirements of practical portable electronic devices. The <2% degradation under light-switching is especially relevant for wearable devices transitioning between sunlight and indoor environments.

Electrochemical Performance of Rechargeable Batteries

A perovskite micro-module (23.60% efficiency, Voc = 4.41 V, four series-connected sub-cells) was integrated with an EVSnI₆ cathode battery to form an all-perovskite integrated photovoltaic battery (PVB). The EVSnI₆ cathode, with a one-dimensional organic-inorganic hybrid structure, enables multi-electron reversible redox reactions (EV⁰/EV⁺/EV²⁺ and I⁻/I⁰/I⁺) at 2.98 V average voltage. Electrochemical performance:

l 296.1 mAh g⁻¹ at 0.5 A g⁻¹; 212.4 mAh g⁻¹ at 5 A g⁻¹

l 89% capacity retention after 10,000 cycles at 5 A g⁻¹ (0.0011% decay per cycle)

The rigid all-perovskite PVB achieved 18.54% overall energy conversion efficiency over 100 photovoltaic charge-discharge cycles. The flexible PVB on PEN substrate reached 17.62% efficiency, maintaining performance after 1,000 bending cycles (8 mm radius) across a temperature range of -20°C to 40°C.

Performance of All-Perovskite Photovoltaic Power Battery (PVB)

The flexible all-perovskite photovoltaic cells, integrated with an intelligent charging protection board, delivered 24-hour uninterrupted power to a commercial continuous glucose monitor — operating stably under sunlight, indoor lighting, and darkness. This marks a milestone for perovskite solar cells in wearable devices: any portable electronic device requiring autonomous power — medical patches, fitness trackers, environmental sensors — can leverage the cordless power supply enabled by lightweight flexible photovoltaic harvesting with integrated storage on a single thin-film platform.

A: All-perovskite photovoltaic cells in this study achieved 26.11% PCE, with the flexible all-perovskite photovoltaic battery delivering 17.62% overall energy conversion efficiency — sufficient for powering wearable electronics like continuous glucose monitors.

A: Maximum power point tracking (MPPT) continuously monitors peak power under sustained illumination, providing long-term stability data that dark storage tests cannot. MPPT analysis confirmed 96.2% PCE retention after 1,000 hours (ISOS-L-1) and only 2% degradation across 30 light-dark cycles for EVI₂-modified perovskite solar cells.

A: EVI₂ (ethyl violete diiodide) is a dual-function material — it forms a surface modification layer suppressing non-radiative recombination (PL lifetime doubled, defect density halved) in perovskite solar cells, while also serving as the structural template for the EVSnI₆ cathode in the integrated perovskite photovoltaic battery.

A: Yes. The flexible PVB demonstrated 24-hour uninterrupted power to a continuous glucose monitor across a temperature range from -20°C to 40°C and maintained performance after 1,000 bending cycles — validating all-perovskite photovoltaic cells as a cordless power supply for next-generation portable electronic devices.

The Perovskite Maximum Power Point Tracking Test MPPT utilizes A+AA+ grade LED solar simulators as aging light sources. With its advanced technology and multifunctional design, it provides robust support for perovskite solar cell research.

▶ Light Source Rating: A+AA+, Spectral Matching Grade A+, Uniformity Grade A, Long-Term Stability Grade A+

▶ Effective Spot Size: ≥250*250mm (customizable)

▶ Adjustable Irradiance: 0.2-1.5 sun, adjustable in 0.1 sun increments

▶ Independently Controllable Power Bands: 300-400 nm / 400-750 nm / 750-1200 nm

Millennial Perovskite Maximum Power Point Tracking (MPPT) Testing is not only a performance verification tool but also provides robust support for perovskite solar cell (PSC) research.