Perovskite solar cells (PSCs) are rapidly advancing and hold promise to replace silicon-based solar panels. This paper explores the fabrication of semi-transparent, scalable perovskite solar modules using manual screen printing technology, eliminating the need for multiple laser scribing steps. A perovskite solar module based on carbon materials and without a hole transport layer was successfully developed, achieving an active area of 900 cm² and a power conversion efficiency of 11.83%. Accelerated aging tests (high humidity, high temperature, and intense solar irradiance) conducted using a Millennial environmental test chamber validated its commercial potential, demonstrating high efficiency and stability suitable for Building-Integrated Photovoltaics (BIPV) applications.

Cell Structure

(a) Solar cell structure (b) Band diagram of cell materials

Substrate: Fluorine-doped tin oxide (FTO) glass (2 mm thick, resistivity 15 Ω/cm²);

Functional layers:

Electron transport layer (ETL): Dense TiO₂ (c-TiO₂) + mesoporous TiO₂ (m-TiO₂) composite;

Insulating layer: Mesoporous ZrO₂ screen-printing paste;

Cathode: Carbon black-graphite composite paste (particle size range 1–20 μm);

Absorber layer: 5-AVA-MAPbI₃ perovskite precursor solution (superior stability compared to MAPbI₃).

Fabrication of 100 cm² perovskite modules

(a) 100 cm² laser etching module (Unit: centimeters) (b) Component structure and layer width schematic diagram

(a) 10×10 cm² perovskite module (5 series cells) (b) 30×30 cm² module (19 series cells)

Substrate Processing:

Laser Grooving: Etch 2mm insulating trenches (1.7cm pitch) in FTO glass to prevent printing overflow.

Trimethanol/IPA/Acetone ultrasonic cleaning + nitrogen drying.

Fully Printed Deposition:

Oxide Layers: c-TiO₂ (50 nm) → m-TiO₂ (500 nm) → ZrO₂ (1 μm) → Step annealing (150°C → 500°C).

Electrode Process: Silver current collector (500°C) → Carbon composite electrode (carbon black + graphite, annealed at 400°C).

Perovskite Film Formation:

Solution immersion: 5-AVA-MAPbI₃ precursor darkroom permeation for 60 min.

Two-step curing: 70°C crystallization + 70% RH humidity treatment (enhances quality and efficiency).

Encapsulation Structure:

Thermal lamination encapsulation (110°C/3–5 min), sacrificing 0.04% efficiency for long-term stability.

5-Cell Series Connection: Single-cell active area 2.8 cm², gradient layer widths prevent short circuits (c-TiO₂ narrowest, carbon electrode widest).

Fabrication of 900 cm² Perovskite Module

Scaling up the 100 cm² design to produce a 900 cm² large-area solar panel. The device fabrication and chemical deposition process for this module is identical to the 100 cm² module.

Scaling Adjustments:

Heating Method: Switch to uniform heating in an oven (replacing hot plates) → Ensure uniform heating to 500°C (prevent thermal stress cracking).

Series Structure: The 900 cm² module consists of 19 perovskite cells connected in series on a single substrate. After laser etching, ultrasonic cleaning with water/IPA/acetone is mandatory (to prevent amplified contamination).

Geometric Parameter Reconfiguration:

Substrate Dimensions: 30×30 cm² (total area 900 cm²).

Layer Width Unchanged: Width of each layer remains identical to the 100 cm² module.

Length Expansion: Length modified to 27 cm → Active area increased to 200 cm² (original 100 cm² module: 14 cm²).

Accelerated Aging Test

Dry Heat Test T₃₅: 35°C (Dark/40-50% RH, 5 hours) → Assess stability under average spring temperatures.

Dry Heat Test T₄₄: 44°C (Dark/40-50% RH, 3 hours) → Simulate summer environmental adaptability.

Dry Heat Test T₇₀: 70°C (Dark/1 hour) → Test accelerated aging threshold.

Humidity Exposure Test RH₇₀: 70% RH (Dark/5 hours) → Analyze high-humidity effects.

Water Immersion Test W₁: Full submersion (23-28°C/100% RH, dark/1 hour) → Simulate stability in water immersion scenarios.

Light Immersion Test L₁₀₀₀: 1000 W/m² illumination (rising to 45°C/40-45% RH, 1 hour) → Measure light-induced degradation performance.

Electrical Performance Parameters of Perovskite Modules

(a) I-V Curve of 100 cm² Module (b) I-V Curve of 900 cm² Module

Electrical Performance Parameters of 100 cm² and 900 cm² Modules

The 100 cm² module exhibits superior performance compared to the 900 cm² module due to lower recombination rates during charge collection at the corresponding electrodes. Since light utilization efficiency is calculated by measuring the ratio of the transparent area to the total module area and multiplying it by the device's power conversion efficiency, charge collection is significantly reduced.

Perovskite Module Stability Performance  

(a) Efficiency Decay Trend After Aging Test (b) Maximum Power Decay Trend  

(a) Open-Circuit Voltage Change (b) Short-Circuit Current Decay  

(a) Maximum Current Decay  (b) Maximum Voltage Change

Optimal Stability: 35°C dry heat test (degradation rate 0.04%/h, lifespan ≈ 250 h);  

Poorest Stability: Water immersion test (degradation rate 0.16%/h, lifespan ≈ 50 h);

Key Phenomena:  

At temperatures of 44°C and above, current (Iₛ, Iₘₐₓ) exhibits exponential decay;  

During illumination testing, Vₒ shows initial fluctuations (photodegradation) followed by accelerated decay;  

Encapsulation causes a slight efficiency reduction (0.04%) but significantly enhances environmental stability.  

This study employs manual screen printing to fabricate hole-transmission-layer-free (HTL-free) carbon-based semi-transparent perovskite solar modules (ST-PSM) with an active area of 900 cm² and a power conversion efficiency (PCE) of 11.83%. Semi-transparency is achieved by optimizing cell spacing, eliminating the conventional laser scribing step, thereby enhancing mechanical stability and reducing costs. Accelerated aging tests under high temperatures (35°C/44°C/70°C), high humidity (70% RH), water immersion, and full sunlight (1000 W/m²) demonstrated the module's high stability and light utilization efficiency (LUE=4.82%), making it suitable for Building-Integrated Photovoltaics (BIPV) window applications.

Millennial Temperature and Humidity Combined Environmental Test Chamber

email：market@millennialsolar.com

The Millennial Temperature and Humidity Combined Environmental Test Chamber utilizes an imported temperature controller, enabling multi-stage temperature programming with high precision and excellent reliability to meet testing requirements under various climatic conditions.

Temperature Range: 20°C to +130°C

Temperature and Humidity Range: 10%RH to 98%RH (at +20°C to +85°C)

Complies with Testing Standards: IEC61215, IEC61730, UL1703, and other testing standards

The Millennial Temperature and Humidity Combined Environmental Test Chamber provides a one-stop climate simulation solution for photovoltaic module testing. It precisely accelerates aging experiments and comprehensively ensures module reliability certification. By leveraging standardized intelligent control to drive industrial upgrades, it provides robust support for breakthroughs in highly stable, scalable perovskite modules.