11. In a PIN diode, the depletion region exists almost completely within the intrinsic region. 12. The factor mainly accounts for carrier recombination as the charge carriers cross the depletion region . 13. This structure suggests that there is no depletion region to separate the device from the substrate. 14. The depletion region will quickly dissipate. 15. The depletion region of a PIN structure extends across the intrinsic region, deep into the device. 16. However, the width of the depletion region ( called the depletion width ) cannot grow without limit. 17. But only those electron-hole pairs generated in and near the depletion region contribute to current generation. 18. The shape of the depletion region creates a wider channel, allowing more current to flow through it. 19. Therefore, letting D and \ Delta V represent the entire depletion region and the potential difference across it, 20. Because the length of the depletion region is narrow and the band gap is high, electrons can tunnel.
