Question: zener diode is based on the principle of
[{'answer': 'Zener breakdown', 'provenance': [{'wikipedia_id': '97835', 'title': 'Zener diode', 'start_paragraph_id': 8, 'start_character': 697, 'end_paragraph_id': 8, 'end_character': 712, 'bleu_score': 1.0, 'section': 'Section::::Operation.\n'}]}]