Cap

In0.53Ga0.47As

p

1 × 1019 cm−3

30 nm

Barrier

In0.52Al0.48As

p

1 × 1019 cm−3

200 nm

Absorber

In0.53Ga0.47As

p

2.5 × 1018 cm−3

150 nm

In0.53Ga0.47As

p

1 × 1018 cm−3

150 nm

In0.53Ga0.47As

p

4 × 1017 cm−3

150 nm

Grading

InGaAlAs

undoped

50 nm

Spacer

In0.52Al0.48As

undoped

100 nm

Charge

In0.52Al0.48As

p

4 × 1017 cm−3

90 nm

Multiplication

In0.52Al0.48As

undoped

150 nm

Buffer

In0.52Al0.48As

n

5 × 1018 cm−3

800 nm

Substrate

InP

n

SI