Ask HJT | Why Do HJT Solar Cells Need Only Four Manufacturing Steps to Deliver High Efficiency?

In modern photovoltaic manufacturing, performance is shaped not only by peak efficiency but also by how efficiently that performance can be produced at scale. Many advanced solar cell architectures rely on increasingly complex, high-temperature processing sequences. Heterojunction (HJT) solar cells take a fundamentally different path — achieving high efficiency through a streamlined, low-temperature manufacturing process completed in just four core steps.

Rather than adding complexity, HJT manufacturing focuses on preserving wafer integrity, minimizing thermal stress, and maintaining excellent surface passivation from start to finish.

In this fourth installment of the Ask HJT series, Dinto Solar breaks down how “four steps” are enough to unlock exceptional performance.

Four Steps — Each Designed for Performance

HJT solar cell manufacturing is essentially a precision engineering process at the atomic scale. Every stage plays a distinct role in building efficiency and reliability.

Step 1 — Cleaning and Texturing

Chemical treatment creates microscopic pyramid structures on an n-type monocrystalline silicon wafer surface.

These structures significantly reduce light reflection and enhance photon absorption, ensuring more incoming sunlight can be converted into electrical energy.

Step 2 — Amorphous Silicon Deposition (PECVD)

Using plasma-enhanced chemical vapor deposition (PECVD), ultra-thin amorphous silicon layers — only a few nanometers thick — are deposited symmetrically on both sides of the wafer.

Two functional layers work together:

• Intrinsic amorphous silicon (i-a-Si): Atomically passivates surface defects, suppressing carrier recombination and enabling exceptionally high open-circuit voltage.

• Doped amorphous silicon (p/n-a-Si): Forms the heterojunction interface and establishes a strong built-in electric field for efficient charge separation and carrier collection.

This step directly defines the core physical advantages of HJT solar cells, including high efficiency potential, low degradation behavior, and excellent temperature coefficient performance.

Step 3 — TCO Thin-film Deposition (PVD)

A transparent conductive oxide (TCO) layer is deposited using magnetron sputtering, a widely adopted physical vapor deposition (PVD) technique.

The layer combines high optical transparency with strong electrical conductivity, allowing light transmission while enabling efficient current extraction.

Step 4 — Screen-printed Metallization

Electrodes are formed through precision screen printing using specialized low-temperature silver paste.

The entire manufacturing process is completed at temperatures below approximately 200 °C — dramatically lower than conventional crystalline silicon technologies.

Avoiding extreme heat prevents structural damage and preserves wafer flatness throughout production.

✅ Correct Answer to Q1: B

Low-Temperature Manufacturing — A Structural Advantage

The simplicity of HJT manufacturing is not merely about fewer steps. It represents a different production philosophy.

Lower Energy Consumption and Carbon Footprint

Key processes in PERC, TOPCon, and many back-contact architectures often exceed 800 °C.

HJT solar cells complete fabrication entirely under low-temperature conditions, significantly reducing energy consumption during production and lowering embedded carbon emissions — aligning closely with global decarbonization targets.

Superior Product Consistency and Yield Stability

Superior product consistency and manufacturing yield are closely linked to process temperature and structural stability during cell fabrication. High-temperature processing used in many conventional solar cell architectures can introduce thermal stress, increasing the risk of wafer warping, micro-cracks, and performance variation across production batches. By contrast, low-temperature heterojunction (HJT) manufacturing significantly reduces thermal deformation, helping preserve wafer integrity and improve yield stability at scale. More uniform cell performance enables tighter module power distribution, reduces mismatch losses, and supports more predictable long-term energy output for power plant operators.

✅ Correct Answers to Q2: A and B

Through continuous optimization of its four-step manufacturing process, Dinto Solar continues advancing nanoscale film uniformity and interface control, enabling mass-produced HJT solar modules exceeding 24% efficiency while translating low-temperature manufacturing advantages into durable, long-term value for project investors.

By combining a streamlined process flow with low-temperature production, HJT solar cells simultaneously enable greener manufacturing, higher production stability, and outstanding device performance.

Fewer steps reduce thermal stress, lower energy consumption, and improve scalability — advantages that ultimately support reliable large-scale deployment and stronger lifecycle returns.

As the industry moves toward higher efficiency and lower carbon intensity, simplicity itself is becoming a powerful technological advantage.