# Material cross-section diagrams: write layers before labels and paths

A material cross-section can be planned as four parts: objects, layers, paths, and labels. Clarify the real structure first and choose the visual style second; this makes it easier to see what needs revision in a first draft. The image below is an existing public pixelforge case, not a new generation for this tutorial.

![Perovskite solar cell layer structure](https://pixelforge.ultraclaw.cc/uploads/case-templates/admin/2026-05-14/XmCQRPrquK6ho8zAqrZlf.jpg)

## 1. Turn the real structure into a component list

Do not describe only a beautiful device diagram. List the layers in your device, state the viewing direction, and specify the order from top to bottom or left to right. The case layer sequence is a reference and must not be treated as your device design.

- Use verified material names or abbreviations for every layer.
- Make the correspondence between the overall cross-section and local inset explicit.
- Decide which structures must remain and which can be simplified.

## 2. Assign a meaning to every arrow

When illumination, carrier transport, and step relationships use the same arrow, readers cannot tell them apart. Specify the object, start, end, and color for each arrow type and reserve space for a legend. Do not ask the model to invent mechanisms that were not provided.

- Keep the same color for an object in the main figure and inset.
- Set path directions from your own structure and research conclusions.
- Omit unsupported numerical or energy-level information.

## 3. Describe layout and text separately

For a landscape figure prepared for a lab meeting, state 16:9 or 3:2 first, then ask for labels outside the structure with non-crossing leader lines. Keep labels short; move long explanations into the caption.

If Chinese text or chemical formulas are inaccurate in the result, shorten labels and reduce their number first. Use your own editing tool to finish precise typography.

```text
Draw a cross-sectional schematic of 【material or device】. Arrange 【component list】 in 【verified layer order】 and show the structure from 【viewing direction】. Use 【color and arrow legend】 for 【verified transport paths】. Place short English labels around the structure on a white background, landscape 3:2. Show only the structures listed above and do not add experimental data.
```

## 4. Check the first draft in two passes

Use the first pass for structure: layer count, order, connections, and arrows. Use the second pass for expression: labels, leader lines, colors, and whitespace. If the structure is wrong, revise the description of the relevant object or relationship instead of changing every style parameter at once.

- Do the layers and material names match the real device?
- Can each arrow and legend item be matched to the text?
- Did the figure introduce data or structures you did not provide?
- Are labels still readable at the size used in the presentation?

Source: https://pixelforge.ultraclaw.cc/learn/guides/material-section-prompts?lang=en

Reference case: https://pixelforge.ultraclaw.cc/learn/cases/perovskite-solar-cell?lang=en