Room-temperature-processed flexible n-InGaZnO/p-Cu₂O heterojunction diodes and high-frequency diode rectifiers

Flexible indium–gallium–zinc–oxide Schottky diode operating beyond 2.45 GHz

“…To date, most research on metaloxide semiconductors has focused on thin-film transistors (TFTs) 7,8,[21][22][23] , and little has been reported on diodes [24][25][26][27][28][29][30] 27), but these were all made on glass substrate using high-temperature annealing processes and hence not applicable to flexible substrates. To the best of our knowledge, the highest frequency obtained on plastic substrates was 27 MHz by IGZOCu 2 O diodes 10 . To date, no flexible metal-oxide diodes, to our knowledge, have been able to reach the benchmark speed of 2.45 GHz.…”

“…There have been highly desirable efforts to develop high-speed Schottky diodes based on metal-oxide semiconductors 10 , organic semiconductors [11][12][13][14] and conventional semiconductors [15][16][17] . Most of these were on glass substrates, for example, pentacene and C 60 pin diodes working as rectifiers up to 300 MHz 18 ; organic pentacene Schottky diodes operating up to 870 MHz 19 ; diodes based on C 60 and tungsten oxide showing a cut-off frequency of 800 MHz 20 .…”

Transparent SnO–SnO2 p–n Junction Diodes for Electronic and Sensing Applications

“…Apart from the rectifying effect, p–n junction devices have been widely used in sensing applications, such as thermometer, photodetector, and radiometer. Transparent all oxide‐based p–n junction diodes have been attracting increasing attention due to the encouraging rectifying performance and the promise of achieving transparent circuits . As its name suggests, a p–n junction consists of serially connected p‐ and n‐type semiconductors, where the operation of the device strongly depends on quality of the interface between n‐ and p‐type semiconductor layers, which may be degraded by interfacial surface roughness, third phase impurity, and the formation of interfacial layer.…”

“…The oxide phase of metal with multivalence state is more inclined to be oxidized or reduced when exposed to higher process temperature or extended processing time, which would lead to the formation of third phase impurity or interfacial layer, degrading the corresponding device performance. So far, a variety of n‐type TSOs with decent electrical performance and visible‐range transparency are available, including indium oxide (In 2 O 3 ), zinc oxide (ZnO), tin dioxide (SnO 2 ), and amorphous gallium–indium–zinc oxide (a‐GIZO) . In comparison to n‐type TSOs, the p‐type counterparts lag in performance.…”

Flexible transparent high-voltage diodes for energy management in wearable electronics

“…ZnO is a "rediscovered" semiconductor receiving remarkable interest on behalf of its unique merits and promising technological applications. Currently, the flexible diodes are all fabricated below 200 °C, using either low-temperature-synthesized oxide [27][28][29][30][31][32][33][34][35] and organic [36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] materials or high-temperature-prepared Si [52][53][54][55][56][57][58][59][60][61][62][63] and Ge [64] materials combined with transfer method [65], as summarized in Figure 1. The highest reverse voltage or breakdown voltage (Vb) of these flexible diodes are no more than 20 V, with an exception in References 55 and 59 where flexible single-crystalline Si wafers (30 μm thick) were used as the active layers.…”