{'fraction_non_alphanumeric': 0.03553581343697946, 'fraction_numerical': 0.007218212104386452, 'mean_word_length': 4.869706840390879, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Investigation of Pd/MoOx/n-Si diodes for bipolar transistor and light-emitting device applications

Sub-stoichiometric molybdenum oxide (MoO x) has recently been investigated for application in high efficiency Si solar cells as a “hole selective” contact. In this paper, we investigate the electrical and light-emitting properties of MoO x-based contacts on Si from the viewpoint of realizing functional bipolar devices such as light-emitting diodes (LEDs) and transistors without any impurity doping of the Si surface. We realized diodes on n-type Si substrates using e-beam physical vapor deposition of Pd/MoO x contacts and compared their behavior to implanted p +n-Si diodes as a reference. In contrast to majority-carrier dominated conduction that occurs in conventional Schottky diodes, Pd/MoO x/n-Si diodes show minority-carrier dominated charge transport with I–V, C–V, and light-emitting characteristics comparable to implanted counterparts. Utilizing such MoO x-based contacts, we also demonstrate a lateral bipolar transistor concept without employing any doped junctions. A detailed C–V analysis confirmed the excessive band-bending in Si corresponding to a high potential barrier ( > 0.90 V) at the MoO x/n-Si interface which, along with the observed amorphous SiO x(Mo) interlayer, plays a role in suppressing the majority-carrier current. An inversion layer at the n-Si surface was also identified comprising a sheet carrier density greater than 8.6 × 10 11 cm − 2, and the MoO x layer was found to be conductive though with a very high resistivity in the 10 4 Ω-cm range. We refer to these diodes as metal/non-insulator/semiconductor diodes and show with our device simulations that they can be mimicked as high-barrier Schottky diodes with an induced inversion layer at the interface.