N-type vs P-type Solar Cells — What's the Difference?

Understanding Silicon Doping

All crystalline silicon solar cells are "doped" with impurities to create an electric field. The type of doping determines whether the cell is P-type or N-type:

• P-type: Silicon doped with boron, creating positive "holes" as majority charge carriers. Used in Mono PERC cells.
• N-type: Silicon doped with phosphorus, creating free electrons as majority charge carriers. Used in TOPCon and HJT cells.

Why N-type Is Superior

1. No Light-Induced Degradation (LID)

P-type cells suffer from boron-oxygen (B-O) defects that cause 1–3% power loss in the first hours of sun exposure. N-type cells use phosphorus doping and are virtually immune to LID, maintaining higher output from day one.

2. Lower Temperature Coefficient

N-type cells achieve −0.29 to −0.32%/°C versus −0.34 to −0.38%/°C for P-type PERC. In hot climates, this means 2–4% more energy annually.

3. Inherent PID Resistance

Potential Induced Degradation affects P-type cells in humid, high-voltage conditions. N-type cells are naturally resistant to PID due to their negative base doping.

4. Higher Efficiency Ceiling

N-type silicon has higher minority carrier lifetime, enabling greater cell efficiency. The current world record for N-type TOPCon is 26.5%, compared to 24.0% for PERC.

5. Lower Degradation Over Time

N-type panels typically degrade at 0.4%/year compared to 0.55%/year for P-type PERC. After 25 years, N-type retains approximately 5% more of its original output.

Comparison Table

Feature	P-type (PERC)	N-type (TOPCon)
Doping element	Boron	Phosphorus
LID susceptibility	Yes (1–3% loss)	Virtually none
PID resistance	Requires treatment	Inherent
Temperature coefficient	−0.34 to −0.38%/°C	−0.29 to −0.32%/°C
Max module efficiency	21.8%	22.8%
Annual degradation	0.55%/year	0.40%/year
Output at year 25	~84.8%	~89.4%
Cost premium	Baseline	+5–8%
LONGi product	Hi-MO 6	Hi-MO 7

The Industry Transition

In 2024, N-type overtook P-type in global manufacturing capacity for the first time. By 2026, N-type TOPCon accounts for approximately 55% of new panel production. LONGi led this transition, being among the first to mass-produce N-type TOPCon panels at scale.

Frequently Asked Questions

Is N-type worth the extra cost?

Yes. The 5–8% price premium is offset by higher efficiency, lower degradation, and better hot-climate performance. Over 25 years, N-type panels generate 5–10% more total energy than PERC equivalents.

Can I tell if a panel is N-type or P-type?

Check the datasheet. N-type panels will specify "N-type TOPCon" or "N-type HJT" as the cell technology. You can also check the first-year degradation — N-type typically guarantees 1% vs 2% for P-type.

Should I still buy P-type panels?

P-type Mono PERC (like LONGi Hi-MO 6) remains a good choice for budget-conscious projects in temperate climates. For hot climates and long-term value, N-type is recommended.